1
|
Gong Z, Dai S, Jiang X, Lee M, Zhu X, Wang H, Lin Z. Variants in KLK11, affecting signal peptide cleavage of kallikrein-related peptidase 11, cause an autosomal-dominant cornification disorder. Br J Dermatol 2023; 188:100-111. [PMID: 36689511 DOI: 10.1093/bjd/ljac029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 09/21/2022] [Accepted: 09/24/2022] [Indexed: 01/22/2023]
Abstract
BACKGROUND Mendelian disorders of cornification (MeDOC) are a group of heterogeneous genodermatoses with different genetic bases. The pathogenesis of a substantial group of MeDOC remains to be elucidated. OBJECTIVES To identify a new causative gene and the pathogenesis of a previously undescribed autosomal-dominant cornification disorder. METHODS Whole-exome sequencing was performed in three families with the novel cornification disorder to identify the disease-causing variants. As the variants were located around the signal peptide (SP) cleavage site of a kallikrein-related peptidase, SP cleavage, subcellular localization and extracellular secretion of the variants were evaluated in eukaryotic overexpression systems by Western blotting or immunocytochemistry. Then the trypsin-like and chymotrypsin-like proteolytic activity of the peptidase and degradation of its catalytic substrate were assayed using the patients' stratum corneum (SC) samples. The morphology of the lamellar bodies and corneodesmosomes (CDs) in the patients' SC was ultrastructurally examined. A mouse model harbouring the equivalent variant was constructed and evaluated histologically. RESULTS We identified two heterozygous variants affecting Gly50 in kallikrein-related peptidase (KLK)11 in a familial case and two sporadic cases with the new disorder, which is characterized by early-onset ichthyosiform erythroderma or erythrokeratoderma. KLK11 belongs to the family of kallikrein-related peptidases participating in skin desquamation by decomposing CDs, a process essential for shedding of the SC. In vitro experiments demonstrated that the variants perturbed the SP cleavage of KLK11, leading to subcellular mislocalization and impaired extracellular secretion of the KLK11 Gly50Glu variant. Both trypsin-like and chymotrypsin-like proteolytic activities were significantly decreased in the patients' SC samples. Reduced proteolysis of desmoglein 1 and delayed degeneration of CDs were detected in patients' SC, indicating delayed skin desquamation. Consistently, the patients showed a thickened, dense SC, indicating abnormal skin desquamation. Mice harbouring the homozygous c.131G>A (p.Gly44Glu) Klk11 variant, which is equivalent to KLK11 c.149G>A (p.Gly50Glu) in humans, exhibited hyperkeratosis and abnormal desquamation, partially recapitulating the phenotype. CONCLUSIONS We provide evidence that variants at Gly50 affecting the SP cleavage of KLK11 cause a new autosomal-dominant cornification disorder with abnormal desquamation. Our findings highlight the essential role of KLKs in maintaining homeostasis of skin keratinization and desquamation.
Collapse
Affiliation(s)
- Zhuoqing Gong
- Department of Dermatology, Peking University First Hospital, Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, National Clinical Research Center for Skin and Immune Diseases, Beijing 100034, China
| | - Shangzhi Dai
- Department of Dermatology, Peking University First Hospital, Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, National Clinical Research Center for Skin and Immune Diseases, Beijing 100034, China
| | - Xingyuan Jiang
- Department of Dermatology, Peking University First Hospital, Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, National Clinical Research Center for Skin and Immune Diseases, Beijing 100034, China
| | - Mingyang Lee
- Department of Dermatology, Peking University First Hospital, Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, National Clinical Research Center for Skin and Immune Diseases, Beijing 100034, China
| | - Xuejun Zhu
- Department of Dermatology, Peking University First Hospital, Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, National Clinical Research Center for Skin and Immune Diseases, Beijing 100034, China
| | - Huijun Wang
- Dermatology Hospital, Southern Medical University, Guangzhou 510091, China
| | - Zhimiao Lin
- Department of Dermatology, Peking University First Hospital, Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, National Clinical Research Center for Skin and Immune Diseases, Beijing 100034, China
- Dermatology Hospital, Southern Medical University, Guangzhou 510091, China
- Department of Dermatology, Xiamen Chang Gung Hospital, Xiamen 361026, China
| |
Collapse
|
2
|
Rabinovitch E, Mihara K, Sananes A, Zaretsky M, Heyne M, Shifman J, Aharoni A, Hollenberg MD, Papo N. A KLK4 proteinase substrate capture approach to antagonize PAR1. Sci Rep 2021; 11:16170. [PMID: 34373558 PMCID: PMC8352894 DOI: 10.1038/s41598-021-95666-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 07/29/2021] [Indexed: 11/08/2022] Open
Abstract
Proteinase-activated receptor-1 (PAR1), triggered by thrombin and other serine proteinases such as tissue kallikrein-4 (KLK4), is a key driver of inflammation, tumor invasiveness and tumor metastasis. The PAR1 transmembrane G-protein-coupled receptor therefore represents an attractive target for therapeutic inhibitors. We thus used a computational design to develop a new PAR1 antagonist, namely, a catalytically inactive human KLK4 that acts as a proteinase substrate-capture reagent, preventing receptor cleavage (and hence activation) by binding to and occluding the extracellular R41-S42 canonical PAR1 proteolytic activation site. On the basis of in silico site-saturation mutagenesis, we then generated KLK4S207A,L185D, a first-of-a-kind 'decoy' PAR1 inhibitor, by mutating the S207A and L185D residues in wild-type KLK4, which strongly binds to PAR1. KLK4S207A,L185D markedly inhibited PAR1 cleavage, and PAR1-mediated MAPK/ERK activation as well as the migration and invasiveness of melanoma cells. This 'substrate-capturing' KLK4 variant, engineered to bind to PAR1, illustrates proof of principle for the utility of a KLK4 'proteinase substrate capture' approach to regulate proteinase-mediated PAR1 signaling.
Collapse
Affiliation(s)
- Eitan Rabinovitch
- Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, National Institute of Biotechnology in the Negev, Ben-Gurion University of the Negev, P.O.B. 653, 84105, Beer-Sheva, Israel
| | - Koishiro Mihara
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Amiram Sananes
- Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, National Institute of Biotechnology in the Negev, Ben-Gurion University of the Negev, P.O.B. 653, 84105, Beer-Sheva, Israel
| | - Marianna Zaretsky
- Department of Life Sciences, National Institute of Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Michael Heyne
- Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, National Institute of Biotechnology in the Negev, Ben-Gurion University of the Negev, P.O.B. 653, 84105, Beer-Sheva, Israel
- Department of Biological Chemistry, The Hebrew University of Jerusalem, Givat Ram Campus, 91906, Jerusalem, Israel
| | - Julia Shifman
- Department of Biological Chemistry, The Hebrew University of Jerusalem, Givat Ram Campus, 91906, Jerusalem, Israel
| | - Amir Aharoni
- Department of Life Sciences, National Institute of Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Morley D Hollenberg
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Niv Papo
- Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, National Institute of Biotechnology in the Negev, Ben-Gurion University of the Negev, P.O.B. 653, 84105, Beer-Sheva, Israel.
| |
Collapse
|
3
|
Li M, Srp J, Mareš M, Wlodawer A, Gustchina A. Structural studies of complexes of kallikrein 4 with wild-type and mutated forms of the Kunitz-type inhibitor BbKI. Acta Crystallogr D Struct Biol 2021; 77:1084-1098. [PMID: 34342281 PMCID: PMC8329858 DOI: 10.1107/s2059798321006483] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 06/21/2021] [Indexed: 11/10/2022] Open
Abstract
Structures of BbKI, a recombinant Kunitz-type serine protease inhibitor from Bauhinia bauhinioides, complexed with human kallikrein 4 (KLK4) were determined at medium-to-high resolution in four crystal forms (space groups P3121, P6522, P21 and P61). Although the fold of the protein was virtually identical in all of the crystals, some significant differences were observed in the conformation of Arg64 of BbKI, the residue that occupies the S1 pocket in KLK4. Whereas this residue exhibited two orientations in the highest resolution structure (P3121), making either a canonical trypsin-like interaction with Asp189 of KLK4 or an alternate interaction, only a single alternate orientation was observed in the other three structures. A neighboring disulfide, Cys191-Cys220, was partially or fully broken in all KLK4 structures. Four variants of BbKI in which Arg64 was replaced by Met, Phe, Ala and Asp were expressed and crystallized, and their structures were determined in complex with KLK4. Structures of the Phe and Met variants complexed with bovine trypsin and of the Phe variant complexed with α-chymotrypsin were also determined. Although the inhibitory potency of these variant forms of BbKI was lowered by up to four orders of magnitude, only small changes were seen in the vicinity of the mutated residues. Therefore, a totality of subtle differences in KLK4-BbKI interactions within the fully extended interface in the structures of these variants might be responsible for the observed effect. Screening of the BbKI variants against a panel of serine proteases revealed an altered pattern of inhibitory specificity, which was shifted towards that of chymotrypsin-like proteases for the hydrophobic Phe and Met P1 substitutions. This work reports the first structures of plant Kunitz inhibitors with S1-family serine proteases other than trypsin, as well as new insights into the specificity of inhibition of medically relevant kallikreins.
Collapse
Affiliation(s)
- Mi Li
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
- Basic Science Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Jaroslav Srp
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague, Czech Republic
| | - Michael Mareš
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague, Czech Republic
| | - Alexander Wlodawer
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Alla Gustchina
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| |
Collapse
|
4
|
Garnuszek P, Karczmarczyk U, Maurin M, Sikora A, Zaborniak J, Pijarowska-Kruszyna J, Jaroń A, Wyczółkowska M, Wojdowska W, Pawlak D, Lipiński PFJ, Mikołajczak R. PSMA-D4 Radioligand for Targeted Therapy of Prostate Cancer: Synthesis, Characteristics and Preliminary Assessment of Biological Properties. Int J Mol Sci 2021; 22:2731. [PMID: 33800517 PMCID: PMC7962978 DOI: 10.3390/ijms22052731] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 02/26/2021] [Accepted: 02/26/2021] [Indexed: 12/25/2022] Open
Abstract
A new PSMA ligand (PSMA-D4) containing the Glu-CO-Lys pharmacophore connected with a new linker system (L-Trp-4-Amc) and chelator DOTA was developed for radiolabeling with therapeutic radionuclides. Herein we describe the synthesis, radiolabeling, and preliminary biological evaluation of the novel PSMA-D4 ligand. Synthesized PSMA-D4 was characterized using TOF-ESI-MS, NMR, and HPLC methods. The novel compound was subject to molecular modeling with GCP-II to compare its binding mode to analogous reference compounds. The radiolabeling efficiency of PSMA-D4 with 177Lu, 90Y, 47Sc, and 225Ac was chromatographically tested. In vitro studies were carried out in PSMA-positive LNCaP tumor cells membranes. The ex vivo tissue distribution profile of the radioligands and Cerenkov luminescence imaging (CLI) was studied in LNCaP tumor-bearing mice. PSMA-D4 was synthesized in 24% yield and purity >97%. The radio complexes were obtained with high yields (>97%) and molar activity ranging from 0.11 to 17.2 GBq mcmol-1, depending on the radionuclide. In vitro assays confirmed high specific binding and affinity for all radiocomplexes. Biodistribution and imaging studies revealed high accumulation in LNCaP tumor xenografts and rapid clearance of radiocomplexes from blood and non-target tissues. These render PSMA-D4 a promising ligand for targeted therapy of prostate cancer (PCa) metastases.
Collapse
Affiliation(s)
- Piotr Garnuszek
- National Centre for Nuclear Research, Radioisotope Centre POLATOM, 05-400 Otwock, Poland; (P.G.); (M.M.); (A.S.); (J.P.-K.); (A.J.); (M.W.); (W.W.); (D.P.); (R.M.)
| | - Urszula Karczmarczyk
- National Centre for Nuclear Research, Radioisotope Centre POLATOM, 05-400 Otwock, Poland; (P.G.); (M.M.); (A.S.); (J.P.-K.); (A.J.); (M.W.); (W.W.); (D.P.); (R.M.)
| | - Michał Maurin
- National Centre for Nuclear Research, Radioisotope Centre POLATOM, 05-400 Otwock, Poland; (P.G.); (M.M.); (A.S.); (J.P.-K.); (A.J.); (M.W.); (W.W.); (D.P.); (R.M.)
| | - Arkadiusz Sikora
- National Centre for Nuclear Research, Radioisotope Centre POLATOM, 05-400 Otwock, Poland; (P.G.); (M.M.); (A.S.); (J.P.-K.); (A.J.); (M.W.); (W.W.); (D.P.); (R.M.)
| | | | - Justyna Pijarowska-Kruszyna
- National Centre for Nuclear Research, Radioisotope Centre POLATOM, 05-400 Otwock, Poland; (P.G.); (M.M.); (A.S.); (J.P.-K.); (A.J.); (M.W.); (W.W.); (D.P.); (R.M.)
| | - Antoni Jaroń
- National Centre for Nuclear Research, Radioisotope Centre POLATOM, 05-400 Otwock, Poland; (P.G.); (M.M.); (A.S.); (J.P.-K.); (A.J.); (M.W.); (W.W.); (D.P.); (R.M.)
| | - Monika Wyczółkowska
- National Centre for Nuclear Research, Radioisotope Centre POLATOM, 05-400 Otwock, Poland; (P.G.); (M.M.); (A.S.); (J.P.-K.); (A.J.); (M.W.); (W.W.); (D.P.); (R.M.)
| | - Wioletta Wojdowska
- National Centre for Nuclear Research, Radioisotope Centre POLATOM, 05-400 Otwock, Poland; (P.G.); (M.M.); (A.S.); (J.P.-K.); (A.J.); (M.W.); (W.W.); (D.P.); (R.M.)
| | - Dariusz Pawlak
- National Centre for Nuclear Research, Radioisotope Centre POLATOM, 05-400 Otwock, Poland; (P.G.); (M.M.); (A.S.); (J.P.-K.); (A.J.); (M.W.); (W.W.); (D.P.); (R.M.)
| | - Piotr F. J. Lipiński
- Department of Neuropeptides, Mossakowski Medical Research Center Polish Academy of Sciences, 02-106 Warsaw, Poland;
| | - Renata Mikołajczak
- National Centre for Nuclear Research, Radioisotope Centre POLATOM, 05-400 Otwock, Poland; (P.G.); (M.M.); (A.S.); (J.P.-K.); (A.J.); (M.W.); (W.W.); (D.P.); (R.M.)
| |
Collapse
|
5
|
Søborg Pedersen K, Baun C, Michaelsen Nielsen K, Thisgaard H, Ingemann Jensen A, Zhuravlev F. Design, Synthesis, Computational, and Preclinical Evaluation of natTi/ 45Ti-Labeled Urea-Based Glutamate PSMA Ligand. Molecules 2020; 25:molecules25051104. [PMID: 32131399 PMCID: PMC7179113 DOI: 10.3390/molecules25051104] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/27/2020] [Accepted: 02/28/2020] [Indexed: 11/16/2022] Open
Abstract
Despite promising anti-cancer properties in vitro, all titanium-based pharmaceuticals have failed in vivo. Likewise, no target-specific positron emission tomography (PET) tracer based on the radionuclide 45Ti has been developed, notwithstanding its excellent PET imaging properties. In this contribution, we present liquid–liquid extraction (LLE) in flow-based recovery and the purification of 45Ti, computer-aided design, and the synthesis of a salan-natTi/45Ti-chelidamic acid (CA)-prostate-specific membrane antigen (PSMA) ligand containing the Glu-urea-Lys pharmacophore. The compound showed compromised serum stability, however, no visible PET signal from the PC3+ tumor was seen, while the ex vivo biodistribution measured the tumor accumulation at 1.1% ID/g. The in vivo instability was rationalized in terms of competitive citrate binding followed by Fe(III) transchelation. The strategy to improve the in vivo stability by implementing a unimolecular ligand design is presented.
Collapse
Affiliation(s)
- Kristina Søborg Pedersen
- Department of Health Technology, Technical University of Denmark, Frederiksborgvej 399, Building 202, 4000 Roskilde, Denmark; (K.S.P.); (K.M.N.); (A.I.J.)
| | - Christina Baun
- Department of Clinical Research, University of Southern Denmark, Sønder Boulevard 29, DK-5000 Odense, Denmark; (C.B.); (H.T.)
- Department of Nuclear Medicine, Odense University Hospital, DK-5000 Odense, Denmark
| | - Karin Michaelsen Nielsen
- Department of Health Technology, Technical University of Denmark, Frederiksborgvej 399, Building 202, 4000 Roskilde, Denmark; (K.S.P.); (K.M.N.); (A.I.J.)
| | - Helge Thisgaard
- Department of Clinical Research, University of Southern Denmark, Sønder Boulevard 29, DK-5000 Odense, Denmark; (C.B.); (H.T.)
- Department of Nuclear Medicine, Odense University Hospital, DK-5000 Odense, Denmark
| | - Andreas Ingemann Jensen
- Department of Health Technology, Technical University of Denmark, Frederiksborgvej 399, Building 202, 4000 Roskilde, Denmark; (K.S.P.); (K.M.N.); (A.I.J.)
| | - Fedor Zhuravlev
- Department of Health Technology, Technical University of Denmark, Frederiksborgvej 399, Building 202, 4000 Roskilde, Denmark; (K.S.P.); (K.M.N.); (A.I.J.)
- Correspondence: ; Tel.: +45-4677-5337
| |
Collapse
|
6
|
Thorpe JH, Edgar EV, Smith KJ, Lewell XQ, Rella M, White GV, Polyakova O, Nassau P, Walker AL, Holmes DS, Pearce AC, Wang Y, Liddle J, Hovnanian A. Evaluation of a crystallographic surrogate for kallikrein 5 in the discovery of novel inhibitors for Netherton syndrome. Acta Crystallogr F Struct Biol Commun 2019; 75:385-391. [PMID: 31045568 PMCID: PMC6497096 DOI: 10.1107/s2053230x19003169] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 03/05/2019] [Indexed: 11/10/2022] Open
Abstract
The inhibition of kallikrein 5 (KLK5) has been identified as a potential strategy for treatment of the genetic skin disorder Netherton syndrome, in which loss-of-function mutations in the SPINK5 gene lead to down-regulation of the endogenous inhibitor LEKTI-1 and profound skin-barrier defects with severe allergic manifestations. To aid in the development of a medicine for this target, an X-ray crystallographic system was developed to facilitate fragment-guided chemistry and knowledge-based drug-discovery approaches. Here, the development of a surrogate crystallographic system in place of KLK5, which proved to be challenging to crystallize, is described. The biochemical robustness of the crystallographic surrogate and the suitability of the system for the study of small nonpeptidic fragments and lead-like molecules are demonstrated.
Collapse
Affiliation(s)
- James H. Thorpe
- GlaxoSmithKline, Medicinal Research Centre, Gunnels Wood Road, Stevenage SG1 2NY, England
| | - Emma V. Edgar
- GlaxoSmithKline, Medicinal Research Centre, Gunnels Wood Road, Stevenage SG1 2NY, England
| | - Kathrine J. Smith
- GlaxoSmithKline, Medicinal Research Centre, Gunnels Wood Road, Stevenage SG1 2NY, England
| | - Xiao Q. Lewell
- GlaxoSmithKline, Medicinal Research Centre, Gunnels Wood Road, Stevenage SG1 2NY, England
| | - Monika Rella
- GlaxoSmithKline, Medicinal Research Centre, Gunnels Wood Road, Stevenage SG1 2NY, England
| | - Gemma V. White
- GlaxoSmithKline, Medicinal Research Centre, Gunnels Wood Road, Stevenage SG1 2NY, England
| | - Oxana Polyakova
- GlaxoSmithKline, Medicinal Research Centre, Gunnels Wood Road, Stevenage SG1 2NY, England
| | - Pamela Nassau
- GlaxoSmithKline, Medicinal Research Centre, Gunnels Wood Road, Stevenage SG1 2NY, England
| | - Ann L. Walker
- GlaxoSmithKline, Medicinal Research Centre, Gunnels Wood Road, Stevenage SG1 2NY, England
| | - Duncan S. Holmes
- GlaxoSmithKline, Medicinal Research Centre, Gunnels Wood Road, Stevenage SG1 2NY, England
| | - Andrew C. Pearce
- GlaxoSmithKline, Medicinal Research Centre, Gunnels Wood Road, Stevenage SG1 2NY, England
| | - Yichen Wang
- INSERM UMR1163 Laboratory of Genetic Skin Diseases, Imagine Institute and Université Paris Descartes–Sorbonne Paris Cité, Paris, France
| | - John Liddle
- GlaxoSmithKline, Medicinal Research Centre, Gunnels Wood Road, Stevenage SG1 2NY, England
| | - Alain Hovnanian
- INSERM UMR1163 Laboratory of Genetic Skin Diseases, Imagine Institute and Université Paris Descartes–Sorbonne Paris Cité, Paris, France
| |
Collapse
|
7
|
Li M, Srp J, Gustchina A, Dauter Z, Mares M, Wlodawer A. Crystal structures of the complex of a kallikrein inhibitor from Bauhinia bauhinioides with trypsin and modeling of kallikrein complexes. Acta Crystallogr D Struct Biol 2019; 75:56-69. [PMID: 30644845 PMCID: PMC6333282 DOI: 10.1107/s2059798318016492] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 11/19/2018] [Indexed: 11/11/2022] Open
Abstract
Structures of a recombinant Kunitz-type serine protease inhibitor from Bauhinia bauhinioides (BbKI) complexed with bovine trypsin were determined in two crystal forms. The crystal structure with the L55R mutant of BbKI was determined in space group P64 at 1.94 Å resolution and that with native BbKI in the monoclinic space group P21 at 3.95 Å resolution. The asymmetric unit of the latter crystals contained 44 independent complexes, thus representing one of the largest numbers of independent objects deposited in the Protein Data Bank. Additionally, the structure of the complex with native BbKI was determined at 2.0 Å resolution from P64 crystals isomorphous to those of the mutant. Since BbKI has previously been found to be a potent inhibitor of the trypsin-like plasma kallikrein, it was also tested against several tissue kallikreins. It was found that BbKI is a potent inhibitor of human tissue kallikrein 4 (KLK4) and the chymotrypsin-like human tissue kallikrein 7 (KLK7). Structures of BbKI complexed with the catalytic domain of human plasma kallikrein were modeled, as well as those with KLK4 and KLK7, and the structures were analyzed in order to identify the interactions that are responsible for inhibitory potency.
Collapse
Affiliation(s)
- Mi Li
- Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Jaroslav Srp
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague, Czech Republic
| | - Alla Gustchina
- Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Zbigniew Dauter
- Synchrotron Radiation Research Section, Macromolecular Crystallography Laboratory, NCI, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Michael Mares
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague, Czech Republic
| | - Alexander Wlodawer
- Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| |
Collapse
|
8
|
Kahler U, Fuchs JE, Goettig P, Liedl KR. An unexpected switch in peptide binding mode: from simulation to substrate specificity. J Biomol Struct Dyn 2018; 36:4072-4084. [PMID: 29210603 PMCID: PMC6334781 DOI: 10.1080/07391102.2017.1407674] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 11/15/2017] [Indexed: 12/12/2022]
Abstract
A ten microsecond molecular dynamics simulation of a kallikrein-related peptidase 7 peptide complex revealed an unexpected change in binding mode. After more than two microseconds unrestrained sampling we observe a spontaneous transition of the binding pose including a 180° rotation around the P1 residue. Subsequently, the substrate peptide occupies the prime side region rather than the cognate non-prime side in a stable conformation. We characterize the unexpected binding mode in terms of contacts, solvent-accessible surface area, molecular interactions and energetic properties. We compare the new pose to inhibitor-bound structures of kallikreins with occupied prime side and find that a similar orientation is adopted. Finally, we apply in silico mutagenesis based on the alternative peptide binding position to explore the prime side specificity of kallikrein-related peptidase 7 and compare it to available experimental data. Our study provides the first microsecond time scale simulation data on a kallikrein protease and shows previously unexplored prime side interactions. Therefore, we expect our study to advance the rational design of inhibitors targeting kallikrein-related peptidase 7, an emerging drug target involved in several skin diseases as well as cancer.
Collapse
Affiliation(s)
- Ursula Kahler
- Faculty of Chemistry and Pharmacy, Institute of General, Inorganic and Theoretical Chemistry, University Innsbruck, Innrain 82, InnsbruckA-6020, Austria
| | - Julian E. Fuchs
- Faculty of Chemistry and Pharmacy, Institute of General, Inorganic and Theoretical Chemistry, University Innsbruck, Innrain 82, InnsbruckA-6020, Austria
| | - Peter Goettig
- Division of Structural Biology, Department of Molecular Biology, University of Salzburg, Billrothstrasse 11, SalzburgA-5020, Austria
| | - Klaus R. Liedl
- Faculty of Chemistry and Pharmacy, Institute of General, Inorganic and Theoretical Chemistry, University Innsbruck, Innrain 82, InnsbruckA-6020, Austria
| |
Collapse
|
9
|
Perez VA, Mangum JE, Hubbard MJ. Direct evidence that KLK4 is a hydroxyapatite-binding protein. Biochem Biophys Res Commun 2017; 495:1896-1900. [PMID: 29229389 DOI: 10.1016/j.bbrc.2017.12.040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 12/07/2017] [Indexed: 11/17/2022]
Abstract
The protease kallikrein 4 (KLK4) plays a pivotal role during dental enamel formation by degrading the major enamel protein, amelogenin, prior to the final steps of enamel hardening. KLK4 dysfunction is known to cause some types of developmental defect in enamel but the mechanisms responsible for transient retention of KLK4 in semi-hardened enamel matrix remain unclear. To address contradictory reports about the affinity of KLK4 for enamel hydroxyapatite-like mineral, we used pure components in quasi-physiological conditions and found that KLK4 binds hydroxyapatite directly. Hypothesising KLK4 self-destructs once amelogenin is degraded, biochemical analyses revealed that KLK4 progressively lost activity, became aggregated, and autofragmented when incubated without substrate in both the presence and absence of reducer. However, with non-ionic detergent present as proxy substrate, KLK4 remained active and intact throughout. These findings prompt a new mechanistic model and line of enquiry into the role of KLK4 in enamel hardening and malformation.
Collapse
Affiliation(s)
- Vidal A Perez
- Department of Pharmacology & Therapeutics, The University of Melbourne, Victoria, Australia; Department of Pediatric Stomatology, University of Talca, Talca, Chile
| | - Jonathan E Mangum
- Department of Pharmacology & Therapeutics, The University of Melbourne, Victoria, Australia
| | - Michael J Hubbard
- Department of Pharmacology & Therapeutics, The University of Melbourne, Victoria, Australia; Department of Paediatrics, The University of Melbourne, Victoria, Australia.
| |
Collapse
|
10
|
Koludarov I, Jackson TN, Brouw BOD, Dobson J, Dashevsky D, Arbuckle K, Clemente CJ, Stockdale EJ, Cochran C, Debono J, Stephens C, Panagides N, Li B, Manchadi MLR, Violette A, Fourmy R, Hendrikx I, Nouwens A, Clements J, Martelli P, Kwok HF, Fry BG. Enter the Dragon: The Dynamic and Multifunctional Evolution of Anguimorpha Lizard Venoms. Toxins (Basel) 2017; 9:E242. [PMID: 28783084 PMCID: PMC5577576 DOI: 10.3390/toxins9080242] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 08/04/2017] [Accepted: 08/04/2017] [Indexed: 01/08/2023] Open
Abstract
While snake venoms have been the subject of intense study, comparatively little work has been done on lizard venoms. In this study, we have examined the structural and functional diversification of anguimorph lizard venoms and associated toxins, and related these results to dentition and predatory ecology. Venom composition was shown to be highly variable across the 20 species of Heloderma, Lanthanotus, and Varanus included in our study. While kallikrein enzymes were ubiquitous, they were also a particularly multifunctional toxin type, with differential activities on enzyme substrates and also ability to degrade alpha or beta chains of fibrinogen that reflects structural variability. Examination of other toxin types also revealed similar variability in their presence and activity levels. The high level of venom chemistry variation in varanid lizards compared to that of helodermatid lizards suggests that venom may be subject to different selection pressures in these two families. These results not only contribute to our understanding of venom evolution but also reveal anguimorph lizard venoms to be rich sources of novel bioactive molecules with potential as drug design and development lead compounds.
Collapse
Affiliation(s)
- Ivan Koludarov
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia QLD 4072, Australia.
| | - Timothy Nw Jackson
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia QLD 4072, Australia.
- Australian Venom Research Unit, School of Biomedical Sciences, Level 2 Medical Building, University of Melbourne, Victoria 3010, Australia.
| | - Bianca Op den Brouw
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia QLD 4072, Australia.
| | - James Dobson
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia QLD 4072, Australia.
| | - Daniel Dashevsky
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia QLD 4072, Australia.
| | - Kevin Arbuckle
- Department of Biosciences, College of Science, Swansea University, Swansea SA2 8PP, UK.
| | - Christofer J Clemente
- University of the Sunshine Coast, School of Science and Engineering, Sippy Downs, Queensland 4558, Australia.
| | | | - Chip Cochran
- Department of Earth and Biological Sciences, Loma Linda University, Loma Linda, CA 92350, USA.
| | - Jordan Debono
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia QLD 4072, Australia.
| | - Carson Stephens
- School of Biomedical Sciences, Queensland University of Technology, Brisbane QLD 4001, Australia.
| | - Nadya Panagides
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia QLD 4072, Australia.
| | - Bin Li
- Faculty of Health Sciences, University of Macau, Avenida da Universidade, Taipa, Macau.
| | | | - Aude Violette
- Alphabiotoxine Laboratory sprl, Barberie 15, 7911 Montroeul-au-bois, Belgium.
| | - Rudy Fourmy
- Alphabiotoxine Laboratory sprl, Barberie 15, 7911 Montroeul-au-bois, Belgium.
| | - Iwan Hendrikx
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia QLD 4072, Australia.
| | - Amanda Nouwens
- School of Chemistry and Molecular Biology, University of Queenslnd, St. Lucia QLD 4072, Australia.
| | - Judith Clements
- School of Biomedical Sciences, Queensland University of Technology, Brisbane QLD 4001, Australia.
| | | | - Hang Fai Kwok
- Faculty of Health Sciences, University of Macau, Avenida da Universidade, Taipa, Macau.
| | - Bryan G Fry
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia QLD 4072, Australia.
| |
Collapse
|
11
|
Debela M, Magdolen V, Bode W, Brandstetter H, Goettig P. Structural basis for the Zn2+ inhibition of the zymogen-like kallikrein-related peptidase 10. Biol Chem 2017; 397:1251-1264. [PMID: 27611765 PMCID: PMC5551965 DOI: 10.1515/hsz-2016-0205] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 09/04/2016] [Indexed: 12/18/2022]
Abstract
Although kallikrein-related peptidase 10 (KLK10) is expressed in a variety of human tissues and body fluids, knowledge of its physiological functions is fragmentary. Similarly, the pathophysiology of KLK10 in cancer is not well understood. In some cancer types, a role as tumor suppressor has been suggested, while in others elevated expression is associated with poor patient prognosis. Active human KLK10 exhibits a unique, three residue longer N-terminus with respect to other serine proteases and an extended 99-loop nearly as long as in tissue kallikrein KLK1. Crystal structures of recombinant ligand-free KLK10 and a Zn2+ bound form explain to some extent the mixed trypsin- and chymotrypsin-like substrate specificity. Zn2+-inhibition of KLK10 appears to be based on a unique mechanism, which involves direct binding and blocking of the catalytic triad. Since the disordered N-terminus and several loops adopt a zymogen-like conformation, the active protease conformation is very likely induced by interaction with the substrate, in particular at the S1 subsite and at the unusual Ser193 as part of the oxyanion hole. The KLK10 structures indicate that the N-terminus, the nearby 75-, 148-, and the 99-loops are connected in an allosteric network, which is present in other trypsin-like serine proteases with several variations.
Collapse
Affiliation(s)
| | - Viktor Magdolen
- Klinische Forschergruppe der Frauenklinik, Klinikum rechts der Isar der TU München, Ismaninger Str. 22, D-81675 München, Germany
| | - Wolfram Bode
- Max-Planck-Institut für Biochemie, Proteinase Research Group, Am Klopferspitz 18, D-82152 Martinsried, Germany
| | - Hans Brandstetter
- Division of Structural Biology, Department of Molecular Biology, University of Salzburg, Billrothstrasse 11, A-5020 Salzburg, Austria
| | | |
Collapse
|
12
|
Huang W, Chang CL, Brault ND, Gur O, Wang Z, Jalal SI, Low PS, Ratliff TL, Pili R, Savran CA. Separation and dual detection of prostate cancer cells and protein biomarkers using a microchip device. Lab Chip 2017; 17:415-428. [PMID: 28054089 DOI: 10.1039/c6lc01279e] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Current efforts for the detection of prostate cancer using only prostate specific antigen are not ideal and indicate a need to develop new assays - using multiple targets - that can more accurately stratify disease states. We previously introduced a device capable of the concurrent detection of cellular and molecular markers from a single sample fluid. Here, an improved design, which achieves affinity as well as size-based separation of captured targets using antibody-conjugated magnetic beads and a silicon chip containing micro-apertures, is presented. Upon injection of the sample, the integration of magnetic attraction with the micro-aperture chip permits larger cell-bead complexes to be isolated in an upper chamber with the smaller protein-bead complexes and remaining beads passing through the micro-apertures into the lower chamber. This enhances captured cell purity for on chip quantification, allows the separate retrieval of captured cells and proteins for downstream analysis, and enables higher bead concentrations for improved multiplexed ligand targeting. Using LNCaP cells and prostate specific membrane antigen (PSMA) to model prostate cancer, the device was able to detect 34 pM of spiked PSMA and achieve a cell capture efficiency of 93% from culture media. LNCaP cells and PSMA were then spiked into diluted healthy human blood to mimic a cancer patient. The device enabled the detection of spiked PSMA (relative to endogenous PSMA) while recovering 85-90% of LNCaP cells which illustrated the potential of new assays for the diagnosis of prostate cancer.
Collapse
Affiliation(s)
- Wanfeng Huang
- School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA. and Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA
| | - Chun-Li Chang
- School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA. and Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA
| | - Norman D Brault
- School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA. and Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA
| | - Onur Gur
- School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA. and Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA
| | - Zhe Wang
- School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA. and Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA
| | - Shadia I Jalal
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Philip S Low
- Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Timothy L Ratliff
- Center for Cancer Research and Department of Comparative Pathobiology, Purdue University, West Lafayette, IN 47907, USA
| | - Roberto Pili
- Genitourinary Program, Roswell Park Cancer Institute, Buffalo, NY 14263, USA and Genitourinary Program, Indiana University-Simon Cancer Center, Indianapolis, IN 46202, USA
| | - Cagri A Savran
- School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA. and Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA and Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA
| |
Collapse
|
13
|
Abstract
Unlike other mineralized tissues, mature dental enamel is primarily (> 95% by weight) composed of apatitic crystals and has a unique hierarchical structure. Due to its high mineral content and organized structure, enamel has exceptional functional properties and is the hardest substance in the human body. Enamel formation (amelogenesis) is the result of highly orchestrated extracellular processes that regulate the nucleation, growth, and organization of forming mineral crystals. However, major aspects of the mechanism of enamel formation are not well-understood, although substantial evidence suggests that protein-protein and protein-mineral interactions play crucial roles in this process. The purpose of this review is a critical evaluation of the present state of knowledge regarding the potential role of the assembly of enamel matrix proteins in the regulation of crystal growth and the structural organization of the resulting enamel tissue. This review primarily focuses on the structure and function of amelogenin, the predominant enamel matrix protein. This review also provides a brief description of novel in vitro approaches that have used synthetic macromolecules ( i.e., surfactants and polymers) to regulate the formation of hierarchical inorganic (composite) structures in a fashion analogous to that believed to take place in biological systems, such as enamel. Accordingly, this review illustrates the potential for developing bio-inspired approaches to mineralized tissue repair and regeneration. In conclusion, the authors present a hypothesis, based on the evidence presented, that the full-length amelogenin uniquely regulates proper enamel formation through a process of cooperative mineralization, and not as a pre-formed matrix.
Collapse
Affiliation(s)
- H C Margolis
- Department of Biomineralization, The Forsyth Institute, 140 The Fenway, Boston, MA 02115, USA.
| | | | | |
Collapse
|
14
|
Rosén P, Rosén S, Ezban M, Persson E. Overestimation of N-glycoPEGylated factor IX activity in a one-stage factor IX clotting assay owing to silica-mediated premature conversion to activated factor IX. J Thromb Haemost 2016; 14:1420-7. [PMID: 27169618 DOI: 10.1111/jth.13359] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 04/21/2016] [Indexed: 01/22/2023]
Abstract
UNLABELLED Essentials Nonacog beta pegol (N9-GP) activity is overestimated in clot method using silica-based reagents. Mimicking contact activation phase with silica reveals N9-GP activation before recalcification. Localization of N9-GP to silica facilitates activation by factor XIa and plasma kallikrein. Silica-based reagents to be used with caution when monitoring N9-GP therapy using clot method. SUMMARY Background Clinical laboratories routinely quantify factor IX (FIX) activity by measurement of the activated partial thromboplastin time (APTT) in a one-stage (OS) clotting assay. This assay can be performed with any of a plethora of differently composed APTT reagents, giving variable recovery when applied to nonacog beta pegol (N9-GP), an N-glycoPEGylated recombinant FIX. Objective To identify the cause of observed overestimations of N9-GP activity in an OS FIX clotting assay when most APTT reagents containing silica are used as the contact activator, and to elucidate the underlying mechanism. Methods Experiments mimicking the contact activation and clotting phases of the OS assay, combined with the use of plasmas with various deficiencies, were employed to shed light on the unique behavior of N9-GP. Confirmatory activations of N9-GP with purified enzymes and physical adsorption to silica particles were studied, and the influence of free polyethylene glycol (PEG) on these processes was investigated. Results N9-GP, but not native FIX, added to FIX-deficient plasma was prematurely converted to activated FIX (FIXa) during the contact activation phase of the clotting assay. Activated FXI (FXIa) and plasma kallikrein (PK) were responsible for the activation of N9-GP, an event that appeared to require the presence of a silica-containing APTT reagent. PEG-dependent adsorption of N9-GP to silica particles could be demonstrated. Conclusions The PEG moiety mediates colocalization of N9-GP with its activators FXIa and PK on silica surfaces, thereby facilitating premature conversion of N9-GP to FIXa during the contact activation phase, and leading to overestimation of the FIX activity in the OS clotting assay.
Collapse
Affiliation(s)
| | | | - M Ezban
- Haemophilia Biology, Novo Nordisk A/S, Måløv, Denmark
| | - E Persson
- Haemophilia Biology, Novo Nordisk A/S, Måløv, Denmark
| |
Collapse
|
15
|
Sukumar N, Scott E, Dimitromanolakis A, Misiak A, Prassas I, Diamandis EP, Konvalinka A. Mining for single nucleotide variants (SNVs) at the kallikrein locus with predicted functional consequences. Biol Chem 2015; 395:1037-50. [PMID: 25153386 DOI: 10.1515/hsz-2014-0136] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 07/03/2014] [Indexed: 12/17/2022]
Abstract
Kallikreins (KLKs) are a group of 15 serine proteases encoded by the KLK locus on chromosome 19. Certain single nucleotide variants (SNVs) within the KLK locus have been linked to human disease. Next-generation sequencing of large human cohorts enables reexamination of genomic variation at the KLK locus. We aimed to identify all KLK-related SNVs and examine their impact on gene regulation and function. To this end, we mined KLK SNVs across Ensembl and Exome Variant Server, with exome-sequencing data from 6503 individuals. PolyPhen-2-based prediction of damaging SNVs and population frequencies of these SNVs were examined. Damaging SNVs were plotted on protein sequence and structure. We identified 4866 SNVs, the largest number of KLK-related SNVs reported. Fourteen percent of noncoding SNVs overlapped with transcription factor binding sites. We identified 602 missense coding SNVs, among which 148 were predicted to be damaging. Nine missense SNVs were common (>1% frequency) and displayed significantly different frequencies between European-American and African-American populations. SNVs predicted to be damaging appeared to alter tertiary structure of KLK1 and KLK6. Similarly, these missense SNVs may affect KLK function, resulting in disease phenotypes. Our study represents a mine of information for those studying KLK-related SNVs and their associations with diseases.
Collapse
|
16
|
Pathak M, Wilmann P, Awford J, Li C, Hamad BK, Fischer PM, Dreveny I, Dekker LV, Emsley J. Coagulation factor XII protease domain crystal structure. J Thromb Haemost 2015; 13:580-91. [PMID: 25604127 PMCID: PMC4418343 DOI: 10.1111/jth.12849] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 01/12/2015] [Indexed: 12/11/2022]
Abstract
BACKGROUND Coagulation factor XII is a serine protease that is important for kinin generation and blood coagulation, cleaving the substrates plasma kallikrein and FXI. OBJECTIVE To investigate FXII zymogen activation and substrate recognition by determining the crystal structure of the FXII protease domain. METHODS AND RESULTS A series of recombinant FXII protease constructs were characterized by measurement of cleavage of chromogenic peptide and plasma kallikrein protein substrates. This revealed that the FXII protease construct spanning the light chain has unexpectedly weak proteolytic activity compared to β-FXIIa, which has an additional nine amino acid remnant of the heavy chain present. Consistent with these data, the crystal structure of the light chain protease reveals a zymogen conformation for active site residues Gly193 and Ser195, where the oxyanion hole is absent. The Asp194 side chain salt bridge to Arg73 constitutes an atypical conformation of the 70-loop. In one crystal form, the S1 pocket loops are partially flexible, which is typical of a zymogen. In a second crystal form of the deglycosylated light chain, the S1 pocket loops are ordered, and a short α-helix in the 180-loop of the structure results in an enlarged and distorted S1 pocket with a buried conformation of Asp189, which is critical for P1 Arg substrate recognition. The FXII structures define patches of negative charge surrounding the active site cleft that may be critical for interactions with inhibitors and substrates. CONCLUSIONS These data provide the first structural basis for understanding FXII substrate recognition and zymogen activation.
Collapse
Affiliation(s)
- M Pathak
- Centre for Biomolecular Sciences, School of Pharmacy, University of Nottingham, Nottingham, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Shropshire TD, Reifert J, Rajagopalan S, Baker D, Feinstein SC, Daugherty PS. Amyloid β peptide cleavage by kallikrein 7 attenuates fibril growth and rescues neurons from Aβ-mediated toxicity in vitro. Biol Chem 2014; 395:109-18. [PMID: 23989112 DOI: 10.1515/hsz-2013-0230] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 08/27/2013] [Indexed: 12/23/2022]
Abstract
The gradual accumulation and assembly of β-amyloid (Aβ) peptide into neuritic plaques is a major pathological hallmark of Alzheimer disease (AD). Proteolytic degradation of Aβ is an important clearance mechanism under normal circumstances, and it has been found to be compromised in those with AD. Here, the extended substrate specificity and Aβ-degrading capacity of kallikrein 7 (KLK7), a serine protease with a unique chymotrypsin-like specificity, was characterized. Preferred peptide substrates of KLK7 identified using a bacterial display substrate library were found to exhibit a consensus motif of RXΦ(Y/F)↓(Y/F)↓(S/A/G/T) or RXΦ(Y/F)↓(S/T/A) (Φ=hydrophobic), which is remarkably similar to the hydrophobic core motif of Aβ (K16L17V18F19F20 A21) that is largely responsible for aggregation propensity. KLK7 was found to cleave after both Phe residues within the core of Aβ42 in vitro, thereby inhibiting Aβ fibril formation and promoting the degradation of preformed fibrils. Finally, the treatment of Aβ oligomer preparations with KLK7, but not inactive pro-KLK7, significantly reduced Aβ42-mediated toxicity to rat hippocampal neurons to the same extent as the known Aβ-degrading protease insulin-degrading enzyme (IDE). Taken together, these results indicate that KLK7 possesses an Aβ-degrading capacity that can ameliorate the toxic effects of the aggregated peptide in vitro.
Collapse
|
18
|
Guo S, Skala W, Magdolen V, Brandstetter H, Goettig P. Sweetened kallikrein-related peptidases (KLKs): glycan trees as potential regulators of activation and activity. Biol Chem 2014; 395:959-76. [PMID: 25153382 DOI: 10.1515/hsz-2014-0140] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2014] [Accepted: 04/29/2014] [Indexed: 02/15/2024]
Abstract
Most kallikrein-related peptidases (KLKs) are N-glycosylated with N-acetylglucosamine2-mannose9 units at Asn-Xaa-Ser/Thr sequons during protein synthesis and translocation into the endoplasmic reticulum. These N-glycans are modified in the Golgi machinery, where additional O-glycosylation at Ser and Thr takes place, before exocytotic release of the KLKs into the extracellular space. Sequons are present in all 15 members of the KLKs and comparative studies for KLKs from natural and recombinant sources elucidated some aspects of glycosylation. Although glycosylation of mammalian KLKs 1, 3, 4, 6, and 8 has been analyzed in great detail, e.g., by crystal structures, the respective function remains largely unclear. In some cases, altered enzymatic activity was observed for KLKs upon glycosylation. Remarkably, for KLK3/PSA, changes in the glycosylation pattern were observed in samples of benign prostatic hyperplasia and prostate cancer with respect to healthy individuals. Potential functions of KLK glycosylation in structural stabilization, protection against degradation, and activity modulation of substrate specificity can be deduced from a comparison with other glycosylated proteins and their regulation. According to the new concept of protein sectors, glycosylation distant from the active site might significantly influence the activity of proteases. Novel pharmacological approaches can exploit engineered glycans in the therapeutical context.
Collapse
|
19
|
Ott C, Ainciburu M, Parent C, Michel S, Roesch C, Vourc'h P, Corcia P, Heuze-Vourc'h N, Jolivet-Reynaud C, Courty Y. Development of monoclonal antibodies to human kallikrein-related peptidase 6 (KLK6) and their use in an immunofluorometric assay for free KLK6. Biol Chem 2014; 395:1119-26. [PMID: 25153392 DOI: 10.1515/hsz-2014-0133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 06/06/2014] [Indexed: 11/15/2022]
Abstract
We have raised monoclonal antibodies against KLK6 and constructed a 'sandwich' type immunoassay using 8A8G3 as capture and 3H3E9 as tracer antibodies. 8A8G3 bound to one side of KLK6, whereas 3H3E9 probably bound near its catalytic site. The assay did not detect complexed forms of KLK6, indicating that it quantifies only free KLK6 (fKLK6). fKLK6 was higher in serum of patients with ovarian cancer (11.34 μg/l±1.37) than in controls (3.39 μg/l±0.42). The cerebrospinal fluid contained high concentrations of fKLK6 (257-965 μg/l). This assay could facilitate the evaluation of fKLK6 in human diseases.
Collapse
|
20
|
Bandiera E, Zanotti L, Fabricio ASC, Bucca E, Squarcina E, Romani C, Tassi R, Bignotti E, Todeschini P, Tognon G, Romagnolo C, Gion M, Sartori E, Maggino T, Pecorelli S, Ravaggi A. Cancer antigen 125, human epididymis 4, kallikrein 6, osteopontin and soluble mesothelin-related peptide immunocomplexed with immunoglobulin M in epithelial ovarian cancer diagnosis. Clin Chem Lab Med 2014; 51:1815-24. [PMID: 24013103 DOI: 10.1515/cclm-2013-0151] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 07/29/2013] [Indexed: 12/17/2022]
Abstract
BACKGROUND Human epididymis protein 4 (HE4), kallikrein 6 (KLK6), osteopontin (OPN) and soluble mesothelin-related peptide (SMRP) are new promising biomarkers that could integrate CA125 in epithelial ovarian cancer (EOC) diagnosis. The autoantibody response to tumor antigens is a potential tool for improving the diagnostic performances of biomarkers. The aim of this study was to assess the diagnostic potential of these biomarkers in the form of free markers and immunocomplexed with immunoglobulin M (IgM). Moreover, we analyzed the association between these markers and clinico-pathological characteristics of EOC patients. METHODS Serum and plasma samples of 60 healthy controls, 60 ovarian benign cysts, 60 endometriosis and 60 EOCs, collected before any treatment, were tested for CICs and free antigens by immunoassays. RESULTS Immunocomplexes were characterized by poor sensitivity and specificity, since they allowed the detection only of a small number of EOC patients and were increased in patients with benign gynecological pathologies. However, the markers in the form of free antigens showed good diagnostic performances. Of note, CA125 and HE4 showed high sensitivity in the detection of the malignancy and HE4 emerged as a useful biomarker in differential diagnosis between EOC and endometriosis. Finally, elevated KLK6 and OPN, were associated with advanced FIGO stage, high grade disease, suboptimally debulked tumor and ascites. CONCLUSIONS This study confirms the diagnostic role of CA125, HE4, KLK6, OPN and SMRP, and for the first time showed that CA125, HE4, KLK6, OPN and SMRP immunocomplexed with IgM are not a potential tool for EOC diagnosis.
Collapse
|
21
|
Abstract
The kallikrein-kinin system (KKS) consists of two major cascades in mammals: “plasma KKS” consisting of high molecular-weight (HMW) kininogen (KNG), plasma kallikrein (KLKB1), and bradykinin (BK); and “tissue KKS” consisting of low molecular-weight (LMW) KNG, tissue kallikreins (KLKs), and [Lys0]-BK. Some components of the KKS have been identified in the fishes, but systematic analyses have not been performed, thus this study aims to define the KKS components in teleosts and pave a way for future physiological and evolutionary studies. Through a combination of genomics, molecular, and biochemical methods, we showed that the entire plasma KKS cascade is absent in teleosts. Instead of two KNGs as found in mammals, a single molecular weight KNG was found in various teleosts, which is homologous to the mammalian LMW KNG. Results of molecular phylogenetic and synteny analyses indicated that the all current teleost genomes lack KLKB1, and its unique protein structure, four apple domains and one trypsin domain, could not be identified in any genome or nucleotide databases. We identified some KLK-like proteins in teleost genomes by synteny and conserved domain analyses, which could be the orthologs of tetrapod KLKs. A radioimmunoassay system was established to measure the teleost BK and we found that [Arg0]-BK is the major circulating form instead of BK, which supports that the teleost KKS is similar to the mammalian tissue KKS. Coincidently, coelacanths are the earliest vertebrate that possess both HMW KNG and KLKB1, which implies that the plasma KKS could have evolved in the early lobe-finned fish and descended to the tetrapod lineage. The co-evolution of HMW KNG and KLKB1 in lobe-finned fish and early tetrapods may mark the emergence of the plasma KKS and a contact activation system in blood coagulation, while teleosts may have retained a single KKS cascade.
Collapse
Affiliation(s)
- Marty Kwok-Shing Wong
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba, Japan
- * E-mail:
| | - Yoshio Takei
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba, Japan
| |
Collapse
|
22
|
Marques PI, Bernardino R, Fernandes T, Green ED, Hurle B, Quesada V, Seixas S. Birth-and-death of KLK3 and KLK2 in primates: evolution driven by reproductive biology. Genome Biol Evol 2013. [PMID: 23204305 PMCID: PMC3542562 DOI: 10.1093/gbe/evs111] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The kallikrein (KLK) gene family comprises the largest uninterrupted locus of serine proteases in the human genome and represents a notable case for studying the evolutionary fate of duplicated genes. In primates, a recent duplication event gave rise to KLK2 and KLK3, both encoding essential proteins for the cascade of seminal plasma liquefaction. We reconstructed the evolutionary history of KLK2 and KLK3 by comparative analysis of the orthologous sequences from 22 primate species, calculated d(N)/d(S) ratios, and addressed the hypothesis of coevolution with their substrates, the semenogelins (SEMG1 and SEMG2). Our findings support the placement of the KLK2-KLK3 duplication in the Catarrhini ancestor and unveil the frequent loss of KLK2 throughout primate evolution by different genomic mechanisms, including unequal crossing-over, deletions, and pseudogenization. We provide evidences for an adaptive evolution of KLK3 toward an expanded enzymatic spectrum, with an effect on the hydrolysis of semen coagulum. Furthermore, we found associations between mating system, the number of SEMG repeat units, and the number of functional KLK2 and KLK3, suggesting complex evolutionary dynamics shaped by reproductive biology.
Collapse
Affiliation(s)
- Patrícia Isabel Marques
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Porto, Portugal
- Department of Biochemistry and Molecular Biology-IUOPA, University of Oviedo, Oviedo, Spain
- Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
| | | | | | - NISC Comparative Sequencing Program
- National Human Genome Research Institute, National Institutes of Health (NIH), Bethesda, Maryland
- NIH Intramural Sequencing Center (NISC), National Human Genome Research Institute, National Institutes of Health, Rockville, Maryland
| | - Eric D. Green
- National Human Genome Research Institute, National Institutes of Health (NIH), Bethesda, Maryland
| | - Belen Hurle
- National Human Genome Research Institute, National Institutes of Health (NIH), Bethesda, Maryland
| | - Victor Quesada
- Department of Biochemistry and Molecular Biology-IUOPA, University of Oviedo, Oviedo, Spain
- *Corresponding author: E-mail: ;
| | - Susana Seixas
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Porto, Portugal
- *Corresponding author: E-mail: ;
| |
Collapse
|
23
|
Sotiropoulou G, Pampalakis G. Targeting the kallikrein-related peptidases for drug development. Trends Pharmacol Sci 2012; 33:623-34. [PMID: 23089221 DOI: 10.1016/j.tips.2012.09.005] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 09/14/2012] [Accepted: 09/19/2012] [Indexed: 11/18/2022]
Abstract
Kallikrein-related peptidases (KLKs) constitute a family of 15 serine proteases. Recent studies have shed light on key physiological functions of KLK enzymes and implicate their deregulation in major human pathologies such as neurodegenerative and inflammatory diseases, skin conditions, asthma, and cancer. Consequently, KLKs have emerged as novel targets for pharmacological intervention. Given the pleiotropic roles of KLKs, both activators and inhibitors of KLK activities are of therapeutic interest. For example, inhibitors of hyperactive KLKs in the epidermis would be effective against excess skin desquamation and inflammation, whereas KLK activators could benefit hyperkeratosis caused by diminished KLK proteolysis. Expression of active KLKs by cancer cells and tissues can be exploited to target prodrugs that are proteolytically cleaved to release a cytotoxic compound or a cytolytic toxin at the site of KLK protease activity. Here, we review current approaches for the design and testing of KLK-based therapeutics.
Collapse
Affiliation(s)
- Georgia Sotiropoulou
- Department of Pharmacy, School of Health Sciences, University of Patras, Greece.
| | | |
Collapse
|
24
|
de Veer SJ, Swedberg JE, Parker EA, Harris JM. Non-combinatorial library screening reveals subsite cooperativity and identifies new high-efficiency substrates for kallikrein-related peptidase 14. Biol Chem 2012; 393:331-41. [PMID: 22505516 DOI: 10.1515/bc-2011-250] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 12/05/2011] [Indexed: 11/15/2022]
Abstract
An array of substrates link the tryptic serine protease, kallikrein-related peptidase 14 (KLK14), to physiological functions including desquamation and activation of signaling molecules associated with inflammation and cancer. Recognition of protease cleavage sequences is driven by complementarity between exposed substrate motifs and the physicochemical signature of an enzyme's active site cleft. However, conventional substrate screening methods have generated conflicting subsite profiles for KLK14. This study utilizes a recently developed screening technique, the sparse matrix library, to identify five novel high-efficiency sequences for KLK14. The optimal sequence, YASR, was cleaved with higher efficiency (k(cat)/K(m)=3.81 ± 0.4 × 10(6) M(-1) s(-1)) than favored substrates from positional scanning and phage display by 2- and 10-fold, respectively. Binding site cooperativity was prominent among preferred sequences, which enabled optimal interaction at all subsites as indicated by predictive modeling of KLK14/substrate complexes. These simulations constitute the first molecular dynamics analysis of KLK14 and offer a structural rationale for the divergent subsite preferences evident between KLK14 and closely related KLKs, KLK4 and KLK5. Collectively, these findings highlight the importance of binding site cooperativity in protease substrate recognition, which has implications for discovery of optimal substrates and engineering highly effective protease inhibitors.
Collapse
Affiliation(s)
- Simon J de Veer
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
| | | | | | | |
Collapse
|
25
|
Sanchez WY, de Veer SJ, Swedberg JE, Hong EJ, Reid JC, Walsh TP, Hooper JD, Hammond GL, Clements JA, Harris JM. Selective cleavage of human sex hormone-binding globulin by kallikrein-related peptidases and effects on androgen action in LNCaP prostate cancer cells. Endocrinology 2012; 153:3179-89. [PMID: 22547569 DOI: 10.1210/en.2012-1011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Stimulation of the androgen receptor via bioavailable androgens, including testosterone and testosterone metabolites, is a key driver of prostate development and the early stages of prostate cancer. Androgens are hydrophobic and as such require carrier proteins, including sex hormone-binding globulin (SHBG), to enable efficient distribution from sites of biosynthesis to target tissues. The similarly hydrophobic corticosteroids also require a carrier protein whose affinity for steroid is modulated by proteolysis. However, proteolytic mechanisms regulating the SHBG/androgen complex have not been reported. Here, we show that the cancer-associated serine proteases, kallikrein-related peptidase (KLK)4 and KLK14, bind strongly to SHBG in glutathione S-transferase interaction analyses. Further, we demonstrate that active KLK4 and KLK14 cleave human SHBG at unique sites and in an androgen-dependent manner. KLK4 separated androgen-free SHBG into its two laminin G-like (LG) domains that were subsequently proteolytically stable even after prolonged digestion, whereas a catalytically equivalent amount of KLK14 reduced SHBG to small peptide fragments over the same period. Conversely, proteolysis of 5α-dihydrotestosterone (DHT)-bound SHBG was similar for both KLKs and left the steroid binding LG4 domain intact. Characterization of this proteolysis fragment by [(3)H]-labeled DHT binding assays revealed that it retained identical affinity for androgen compared with full-length SHBG (dissociation constant = 1.92 nM). Consistent with this, both full-length SHBG and SHBG-LG4 significantly increased DHT-mediated transcriptional activity of the androgen receptor compared with DHT delivered without carrier protein. Collectively, these data provide the first evidence that SHBG is a target for proteolysis and demonstrate that a stable fragment derived from proteolysis of steroid-bound SHBG retains binding function in vitro.
Collapse
Affiliation(s)
- Washington Y Sanchez
- Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove, Brisbane, Queensland 4059, Australia
| | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Zhang Y, Xu W, Ma B, Huang K, Song M, Zhang N, Zhang Y, Wang Y, Dai Y, Luo Y. Isolation and characterisation of a kallikrein-like enzyme from Agkistrodon halys pallas snake venom. J Sci Food Agric 2012; 92:1497-1503. [PMID: 22162083 DOI: 10.1002/jsfa.4733] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2011] [Revised: 09/16/2011] [Accepted: 10/04/2011] [Indexed: 05/31/2023]
Abstract
BACKGROUND Viper snake venoms contain a great variety of toxic proteins. These components mediate their toxicity by either stimulating or inhibiting the haemostatic system of human victims or experimental animals, resulting in common clinical complications of blood clotting or uncontrolled haemorrhage. Therefore it is deemed important to isolate the active component(s) from snake venom with kallikrein-like activity. RESULTS A kallikrein-like proteinase of Agkistrodon halys pallas snake venom, designated AHP-Ka, was purified by anion exchange chromatography and affinity chromatography. Physicochemical studies showed that the purified enzyme was a 34 kDa monomeric glycoprotein, the molecular weight of which decreased to 26 kDa after deglycosylation with peptide N-glycosidase F (PNGase F). Sequence studies on the NH(2) -terminal region of the protein indicated that AHP-Ka shared a high degree of sequence homology with other serine proteinases from snake venoms. AHP-Ka showed high catalytic activity and kallikrein-like activity on substrates such as arginine esterase BAEE and chromogenic H-D-Pro-Phe-Arg-pNA·2HCl (S-2302) and was inhibited by protease inhibitor phenylmethylsulfonyl fluoride (PMSF). CONCLUSION The results showed that AHP-Ka isolated from A. halys pallas snake venom and purified by anion exchange chromatography and affinity chromatography is in fact a kallikrein-like enzyme.
Collapse
Affiliation(s)
- Yanan Zhang
- Laboratory of Food Safety, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Stura EA, Muller BH, Bossus M, Michel S, Jolivet-Reynaud C, Ducancel F. Crystal structure of human prostate-specific antigen in a sandwich antibody complex. J Mol Biol 2011; 414:530-44. [PMID: 22037582 DOI: 10.1016/j.jmb.2011.10.007] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 10/04/2011] [Accepted: 10/05/2011] [Indexed: 11/18/2022]
Abstract
Human prostate-specific antigen (PSA or human kallikrein-related peptidase 3) present in small quantities in the sera of healthy men becomes elevated in prostate cancer (PCa) and other prostate disorders. The ability to identify the free PSA fraction associated with PCa could increase the reliability of the PSA diagnostic test. Here we present the crystal structure of human PSA from seminal fluid in a sandwich complex with two monoclonal antibodies (mAbs). MAb 5D5A5 captures total PSA with exceptionally high affinity, and mAb 5D3D11 selectively discriminates between free PSA subforms that are more abundant in sera from patients with PCa. Although the antigen is not of seric origin, several insights into cancer diagnosis can be discerned from this complex. MAb 5D3D11 recognizes a PSA conformation different from that previously reported. Interacting with the kallikrein loop, the PSA N-linked glycan attached to asparagine 61 is an uncommonly complex sialated triantennary chain. O-linked glycosylation is observed at threonine 125. The description of how PSA subforms in prostatic fluid can be discriminated using pairs of antibodies is a first step in the design of new strategies that are capable of real discrimination among PSA subforms, which will lead to the formulation of more reliable diagnostic tests. In a companion article [Muller, B. H., Savatier, A., L'Hostis, G., Costa, N., Bossus, M., Michel, S., et al. (2011). In vitro affinity maturation of an anti-PSA antibody for prostate cancer diagnostic assay. J. Mol. Biol.], we describe engineering efforts to improve the affinity of mAb 5D3D11, a first step towards such goal.
Collapse
Affiliation(s)
- Enrico A Stura
- CEA, iBiTec-S, Service d'Ingénierie Moléculaire des Protéines, Laboratoire de Toxinologie Moléculaire et Biotechnologies, Gif-sur-Yvette F-91191, France.
| | | | | | | | | | | |
Collapse
|
28
|
Angelopoulou K, Karagiannis GS. Structural characterization and expression of five novel canine kallikrein-related peptidases in mammary cancer. Mamm Genome 2010; 21:516-24. [PMID: 20853168 DOI: 10.1007/s00335-010-9282-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Accepted: 09/01/2010] [Indexed: 11/28/2022]
Abstract
Kallikrein-related peptidases (KLKs) constitute a major family of proteolytic enzymes implicated in the pathogenesis of many diseases, including cancer. Recently, we have suggested that the dog might represent a useful animal model for in vivo KLK studies and sought to investigate the expression patterns of the largely unknown canine KLK family. Along the same lines, in the present report we experimentally characterized five previously unidentified (CANFA)KLKs and investigated their expression in normal and tumorous mammary tissues. We demonstrated that the GenBank sequences that were predicted in silico to represent the canine orthologs of human KLK5, KLK6, KLK7, and KLK8 mRNAs were correct, whereas the one corresponding to the canine KLK4 had a major inconsistency within its 5'-terminus. More specifically, two internal segments of the first intron of KLK4, 78 and 97 bp long, respectively, were wrongfully determined to constitute the initial 175-nucleotide sequence of the KLK4 coding region. (CANFA)KLK8 was further shown to undergo alternative splicing that generated an mRNA transcript missing exon 4 (variant 1). All five (CANFA)KLKs were almost ubiquitously expressed in both cancerous and noncancerous mammary tissues. Lower positivity rates were identified for (CANFA)KLK8 variant 1. A trend for upregulation in tumors was observed for (CANFA)KLK5, (CANFA)KLK7, and (CANFA)KLK8, whereas (CANFA)KLK8 variant 1 tended to be downregulated in cancer. Moreover, a parallel expression of the studied canine KLKs was observed, which suggested a possible participation of the encoded enzymes in interrelated proteolytic cascades taking place in the mammary gland.
Collapse
Affiliation(s)
- Katerina Angelopoulou
- Laboratory of Biochemistry and Toxicology, School of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki, 54124, Greece.
| | | |
Collapse
|
29
|
Vaiyapuri S, Harrison RA, Bicknell AB, Gibbins JM, Hutchinson G. Purification and functional characterisation of rhinocerase, a novel serine protease from the venom of Bitis gabonica rhinoceros. PLoS One 2010; 5:e9687. [PMID: 20300193 PMCID: PMC2837349 DOI: 10.1371/journal.pone.0009687] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Accepted: 02/17/2010] [Indexed: 11/18/2022] Open
Abstract
Background Serine proteases are a major component of viper venoms and are thought to disrupt several distinct elements of the blood coagulation system of envenomed victims. A detailed understanding of the functions of these enzymes is important both for acquiring a fuller understanding of the pathology of envenoming and because these venom proteins have shown potential in treating blood coagulation disorders. Methodology/Principal Findings In this study a novel, highly abundant serine protease, which we have named rhinocerase, has been isolated and characterised from the venom of Bitis gabonica rhinoceros using liquid phase isoelectric focusing and gel filtration. Like many viper venom serine proteases, this enzyme is glycosylated; the estimated molecular mass of the native enzyme is approximately 36kDa, which reduces to 31kDa after deglycosylation. The partial amino acid sequence shows similarity to other viper venom serine proteases, but is clearly distinct from the sequence of the only other sequenced serine protease from Bitis gabonica. Other viper venom serine proteases have been shown to exert distinct biological effects, and our preliminary functional characterization of rhinocerase suggest it to be multifunctional. It is capable of degrading α and β chains of fibrinogen, dissolving plasma clots and of hydrolysing a kallikrein substrate. Conclusions/Significance A novel multifunctional viper venom serine protease has been isolated and characterised. The activities of the enzyme are consistent with the known in vivo effects of Bitis gabonica envenoming, including bleeding disorders, clotting disorders and hypotension. This study will form the basis for future research to understand the mechanisms of serine protease action, and examine the potential for rhinocerase to be used clinically to reduce the risk of human haemostatic disorders such as heart attacks and strokes.
Collapse
Affiliation(s)
- Sakthivel Vaiyapuri
- School of Biological Sciences, University of Reading, Reading, United Kingdom
| | - Robert A. Harrison
- The Alistair Reid Venom Research Unit, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Andrew B. Bicknell
- School of Biological Sciences, University of Reading, Reading, United Kingdom
| | - Jonathan M. Gibbins
- School of Biological Sciences, University of Reading, Reading, United Kingdom
- Blood Transfusion Research Group, King Saud University, Riyadh, Saudi Arabia
| | - Gail Hutchinson
- School of Biological Sciences, University of Reading, Reading, United Kingdom
- * E-mail:
| |
Collapse
|
30
|
Fischer M, Sperling C, Werner C. Synergistic effect of hydrophobic and anionic surface groups triggers blood coagulation in vitro. J Mater Sci Mater Med 2010; 21:931-937. [PMID: 19851837 DOI: 10.1007/s10856-009-3912-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2009] [Accepted: 10/09/2009] [Indexed: 05/28/2023]
Abstract
Biomaterial induced coagulation encompasses plasmatic and cellular processes. The functional loss of biomedical devices possibly resulting from these thrombotic reactions motivates the need for a better understanding of processes occurring at blood-biomaterial interfaces. Well defined model surfaces providing specific chemical-physical properties (self assembled monolayers (SAMs)) displaying hydrophobic or/and acidic terminal groups were used to uncover initial mechanisms of biomaterial induced coagulation. We investigated the influence of electrical charge and wettability on platelet- and contact activation, the two main actors of blood coagulation, which are often considered as separate mechanisms in biomaterials research. Our results show a dependence of contact activation on acidic surface groups and a correlation of platelet adhesion to surface hydrophobicity. Clot formation resulting from the interplay of blood platelets and contact activation was only found on surfaces combining both acidic and hydrophobic surface groups but not on monolayers displaying extreme hydrophobic/acidic properties.
Collapse
Affiliation(s)
- Marion Fischer
- Max Bergmann Center of Biomaterials Dresden, Leibniz Institute of Polymer Research Dresden, Dresden, Germany.
| | | | | |
Collapse
|
31
|
Kong HJ, Hong GE, Nam BH, Kim YO, Kim WJ, Lee SJ, Lee NS, Do JW, Cho HK, Cheong J, Lee CH, Kim KK. An immune responsive complement factor D/adipsin and kallikrein-like serine protease (PoDAK) from the olive flounder Paralichthys olivaceus. Fish Shellfish Immunol 2009; 27:486-492. [PMID: 19591942 DOI: 10.1016/j.fsi.2009.06.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2009] [Revised: 06/26/2009] [Accepted: 06/26/2009] [Indexed: 05/28/2023]
Abstract
The cDNA encoding of a complement factor D/adipsin and kallikrein-like serine protease, designated PoDAK, was isolated from the olive flounder Paralichthys olivaceus. PoDAK cDNA encodes a polypeptide with 277 amino acids containing conserved catalytic triad residues of serine proteases. The amino acid sequence of PoDAK showed high similarity to the kallikrein-like protein of medaka, mammalian adipsin/complement factor D and tissue kallikrein homolog, KT-14 of trout, complement factor D of zebrafish, and shared 31.6-36.8% homology with complement factor D/adipsin known from other species, including mammals. Phylogenetic analysis revealed that PoDAK clustered with the kallikrein-like protein of medaka and mammalian adipsin/complement factor D and tissue kallikrein homolog KT-14 of trout. The expression of PoDAK mRNA was high in the gills and heart, moderate in muscle, liver, intestine, stomach, kidney, and spleen of healthy flounder, and increased in the kidney, liver, and spleen of flounder challenged by the viral hemorrhagic septicemia virus (VHSV) or Streptococcus iniae. In situ hybridization confirmed that PoDAK mRNA is localized in the kidney and heart of individuals infected with VHSV. Further investigations are needed to clarify the function of PoDAK in vivo and in vitro.
Collapse
Affiliation(s)
- Hee Jeong Kong
- Biotechnology Research Division, National Fisheries Research and Development Institute, 408-1 Sirang-ri, Gijang-up, Gijang-gun, Busan 619-705, Republic of Korea.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Abe H, Fujihara M, Azuma H, Ikeda H, Ikebuchi K, Takeoka S, Tsuchida E, Harashima H. Interaction of Hemoglobin Vesicles, a Cellular-Type Artificial Oxygen Carrier, with Human Plasma: Effects on Coagulation, Kallikrein-Kinin, and Complement Systems. ACTA ACUST UNITED AC 2009; 34:1-10. [PMID: 16519400 DOI: 10.1080/00207450500428204] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Hemoglobin vesicles (HbVs), cellular-type artificial oxygen carriers containing human hemoglobin, were assessed for their biocompatibility by mixing with human plasma in vitro. Among three kinds of HbVs (PEG-DPEA-HbV, PEG-DPPG-HbV and DPPG-HbV), PEG-DPEA-HbV did not affect the extrinsic or intrinsic coagulation activities of the plasma, while PEG-DPPG-HbV and DPPG-HbV tended to shorten the intrinsic coagulation time. The kallikrein-kinin cascade of the plasma was slightly activated by PEG-DPPG-HbV and DPPG-HbV, but not by PEG-DPEA-HbV. The complement consumption of the plasma was observed by incubation with DPPG-HbV, but not with PEG-DPEA-HbV or PEG-DPPG-HbV. These results indicate that PEG-DPEA-HbV has a higher biocompatibility with human plasma.
Collapse
Affiliation(s)
- Hideki Abe
- Hokkaido Red Cross Blood Center, Japanese Red Cross, Yamanote 2-2, Nishi-ku, Sapporo 063-0002, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Abstract
Kallikrein 1 (KLK1), a key component of the kallikrein-kinin system, originates from a locus on the long arm of chromosome 19 that contains several related serine endopeptidases. The biological role of these kallikrein-related peptidases is not clear, but emerging evidence suggests that they might be important in several physiological systems, e.g., in male reproduction, skin homeostasis, tooth enamel formation and neural development and plasticity. The kallikrein locus has undergone some major evolutionary events. Most spectacular are relatively recent duplications of KLK1 that have created 13 and 9 functional genes that are unique to the mouse and the rat, respectively. Human paralogs are KLK2 and KLK3: the latter encoding the cancer biomarker prostate-specific antigen. In this review on kallikrein-related peptidases, the focus is on their evolution, their role in skin homeostasis and semen liquefaction, and their utility as cancer biomarkers.
Collapse
Affiliation(s)
- A Lundwall
- Department of Laboratory Medicine Malmö, Clinical Chemistry, Lund University, University Hospital MAS, Malmö, Sweden.
| | | |
Collapse
|
34
|
Abstract
Venom is a key innovation underlying the evolution of advanced snakes (Caenophidia). Despite this, very little is known about venom system structural diversification, toxin recruitment event timings, or toxin molecular evolution. A multidisciplinary approach was used to examine the diversification of the venom system and associated toxins across the full range of the approximately 100 million-year-old advanced snake clade with a particular emphasis upon families that have not secondarily evolved a front-fanged venom system ( approximately 80% of the 2500 species). Analysis of cDNA libraries revealed complex venom transcriptomes containing multiple toxin types including three finger toxins, cobra venom factor, cysteine-rich secretory protein, hyaluronidase, kallikrein, kunitz, lectin, matrix metalloprotease, phospholipase A(2), snake venom metalloprotease/a disintegrin and metalloprotease, and waprin. High levels of sequence diversity were observed, including mutations in structural and functional residues, changes in cysteine spacing, and major deletions/truncations. Morphological analysis comprising gross dissection, histology, and magnetic resonance imaging also demonstrated extensive modification of the venom system architecture in non-front-fanged snakes in contrast to the conserved structure of the venom system within the independently evolved front-fanged elapid or viperid snakes. Further, a reduction in the size and complexity of the venom system was observed in species in which constriction has been secondarily evolved as the preferred method of prey capture or dietary preference has switched from live prey to eggs or to slugs/snails. Investigation of the timing of toxin recruitment events across the entire advanced snake radiation indicates that the evolution of advanced venom systems in three front-fanged lineages is associated with recruitment of new toxin types or explosive diversification of existing toxin types. These results support the role of venom as a key evolutionary innovation in the diversification of advanced snakes and identify a potential role for non-front-fanged venom toxins as a rich source for lead compounds for drug design and development.
Collapse
Affiliation(s)
- Bryan G Fry
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3010, Australia.
| | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Debela M, Goettig P, Magdolen V, Huber R, Schechter NM, Bode W. Structural Basis of the Zinc Inhibition of Human Tissue Kallikrein 5. J Mol Biol 2007; 373:1017-31. [PMID: 17881000 DOI: 10.1016/j.jmb.2007.08.042] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2007] [Revised: 07/30/2007] [Accepted: 08/19/2007] [Indexed: 11/22/2022]
Abstract
Human kallikrein 5 (hK5) is a member of the tissue kallikrein family of serine peptidases. It has trypsin-like substrate specificity, is inhibited by metal ions, and is abundantly expressed in human skin, where it is believed to play a central role in desquamation. To further understand the interaction of hK5 with substrates and metal ions, active recombinant hK5 was crystallized in complex with the tripeptidyl aldehyde inhibitor leupeptin, and structures at 2.3 A resolution were obtained with and without Zn2+. While the overall structure and the specificity of S1 pocket for basic side-chains were similar to that of hK4, a closely related family member, both differed in their interaction with Zn2+. Unlike hK4, the 75-loop of hK5 is not structured to bind a Zn2+. Instead, Zn2+ binds adjacent to the active site, becoming coordinated by the imidazole rings of His99 and His96 not present in hK4. This zinc binding is accompanied by a large shift in the backbone conformation of the 99-loop and by large movements of both His side-chains. Modeling studies show that in the absence of bound leupeptin, Zn2+ is likely further coordinated by the imidazolyl side-chain of the catalytic His57 which can, similar to equivalent His57 imidazole groups in the related rat kallikrein proteinase tonin and in an engineered metal-binding rat trypsin, rotate out of its triad position to provide the third co-ordination site of the bound Zn2+, rendering Zn2+-bound hK5 inactive. In solution, this mode of binding likely occurs in the presence of free and substrate saturated hK5, as kinetic analyses of Zn2+ inhibition indicate a non-competitive mechanism. Supporting the His57 re-orientation, Zn2+ does not fully inhibit hK5 hydrolysis of tripeptidyl substrates containing a P2-His residue. The P2 and His57 imidazole groups would lie next to each other in the enzyme-substrate complex, indicating that incomplete inhibition is due to competition between both imidazole groups for Zn2+. The His96-99-57 triad is thus suggested to be responsible for the Zn2+-mediated inhibition of hK5 catalysis.
Collapse
Affiliation(s)
- Mekdes Debela
- Max-Planck-Institut für Biochemie, Proteinase Research Group, Am Klopferspitz 18, 82152 Martinsried, Germany
| | | | | | | | | | | |
Collapse
|
36
|
Debela M, Hess P, Magdolen V, Schechter NM, Steiner T, Huber R, Bode W, Goettig P. Chymotryptic specificity determinants in the 1.0 A structure of the zinc-inhibited human tissue kallikrein 7. Proc Natl Acad Sci U S A 2007; 104:16086-91. [PMID: 17909180 PMCID: PMC2042166 DOI: 10.1073/pnas.0707811104] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
hK7 or human stratum corneum chymotryptic enzyme belongs to the human tissue kallikrein (hKs) serine proteinase family and is strongly expressed in the upper layers of the epidermis. It participates in skin desquamation but is also implicated in diverse skin diseases and is a potential biomarker of ovarian cancer. We have solved x-ray structures of recombinant active hK7 at medium and atomic resolution in the presence of the inhibitors succinyl-Ala-Ala-Pro-Phe-chloromethyl ketone and Ala-Ala-Phe-chloromethyl ketone. The most distinguishing features of hK7 are the short 70-80 loop and the unique S1 pocket, which prefers P1 Tyr residues, as shown by kinetic data. Similar to several other kallikreins, the enzyme activity is inhibited by Zn(2+) and Cu(2+) at low micromolar concentrations. Biochemical analyses of the mutants H99A and H41F confirm that only the metal-binding site at His(99) close to the catalytic triad accounts for the noncompetitive Zn(2+) inhibition type. Additionally, hK7 exhibits large positively charged surface patches, representing putative exosites for prime side substrate recognition.
Collapse
Affiliation(s)
- Mekdes Debela
- Max-Planck-Institut für Biochemie, Proteinase Research Group, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Petra Hess
- Max-Planck-Institut für Biochemie, Strukturforschung, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Viktor Magdolen
- Klinische Forschergruppe der Frauenklinik der TU München, Ismaninger Strasse 22, 81675 Munich, Germany
| | - Norman M. Schechter
- Department of Dermatology, University of Pennsylvania, 415 Curie Boulevard, Philadelphia, PA 19104; and
| | - Thomas Steiner
- Max-Planck-Institut für Biochemie, Strukturforschung, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Robert Huber
- Max-Planck-Institut für Biochemie, Strukturforschung, Am Klopferspitz 18, 82152 Martinsried, Germany
- School of Biosciences, Cardiff University, Cardiff CF10 3TL, United Kingdom
- To whom correspondence may be addressed. E-mail: or
| | - Wolfram Bode
- Max-Planck-Institut für Biochemie, Proteinase Research Group, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Peter Goettig
- Max-Planck-Institut für Biochemie, Proteinase Research Group, Am Klopferspitz 18, 82152 Martinsried, Germany
- To whom correspondence may be addressed. E-mail: or
| |
Collapse
|
37
|
Yoon H, Laxmikanthan G, Lee J, Blaber SI, Rodriguez A, Kogot JM, Scarisbrick IA, Blaber M. Activation profiles and regulatory cascades of the human kallikrein-related peptidases. J Biol Chem 2007; 282:31852-64. [PMID: 17823117 DOI: 10.1074/jbc.m705190200] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The human kallikrein (KLK)-related peptidases are the largest family of serine peptidases, comprising 15 members (KLK1-15) and with the majority (KLK4-15) being identified only within the last decade. Members of this family are associated with important diseased states (including cancer, inflammation, and neurodegeneration) and have been utilized or proposed as clinically important biomarkers or therapeutic targets of interest. All human KLKs are synthesized as prepro-forms that are proteolytically processed to secreted pro-forms via the removal of an amino-terminal secretion signal peptide. The secreted inactive pro-KLKs are then activated extracellularly to mature peptidases by specific proteolytic release of their amino-terminal propeptide. Although a key step in the regulation of KLK function, details regarding the activation of the human pro-KLKs (i.e. the KLK "activome") are unknown, to a significant extent, but have been postulated to involve "activation cascades" with other KLKs and endopeptidases. To characterize more completely the KLK activome, we have expressed from Escherichia coli individual KLK propeptides fused to the amino terminus of a soluble carrier protein. The ability of 12 different mature KLKs to process the 15 different pro-KLK peptide sequences has been determined. Various autolytic and cross-activation relationships identified using this system have subsequently been characterized using recombinant pro-KLK proteins. The results demonstrate the potential for extensive KLK activation cascades and, when combined with available data for the tissue-specific expression of the KLK family, permit the construction of specific regulatory cascades. One such tissue-specific cascade is proposed for the central nervous system.
Collapse
Affiliation(s)
- Hyesook Yoon
- Department of Biomedical Sciences, Florida State University, Tallahassee, Florida 32306-4300, USA
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Fernández IS, Ständker L, Forssmann WG, Giménez-Gallego G, Romero A. Crystallization and preliminary crystallographic studies of human kallikrein 7, a serine protease of the multigene kallikrein family. Acta Crystallogr Sect F Struct Biol Cryst Commun 2007; 63:669-72. [PMID: 17671364 PMCID: PMC2335154 DOI: 10.1107/s1744309107031764] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2007] [Accepted: 06/28/2007] [Indexed: 11/10/2022]
Abstract
Human kallikreins are a group of serine proteases of high sequence homology whose genes are grouped as a single cluster at chromosome 19. Although the physiological roles of kallikreins are generally still unknown, members of the kallikrein family have been clearly implicated in pathological situations such as cancer and psoriasis. Human kallikrein 7 (hK7) has been shown to be involved in pathological keratinization, psoriasis and ovarian cancer. In order to gain insight into the molecular structure of this protein, hK7 was crystallized after recombinant production in its folded and active form using a periplasmic secretion vector in Escherichia coli. The crystals belonged to the rhombohedral space group H32 and diffracted to 2.8 A. The phase problem was solved by molecular replacement using the mouse kallikrein-related protein neuropsin. Completion of the model and structure refinement are under way.
Collapse
Affiliation(s)
- Israel S. Fernández
- Departamento de Ciencia de Proteínas, Centro de Investigaciones Biológicas–CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Ludger Ständker
- Departamento de Ciencia de Proteínas, Centro de Investigaciones Biológicas–CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
- Hannover Medical School, Center of Pharmacology, 30625 Hannover, Germany
| | | | - Guillermo Giménez-Gallego
- Departamento de Ciencia de Proteínas, Centro de Investigaciones Biológicas–CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Antonio Romero
- Departamento de Ciencia de Proteínas, Centro de Investigaciones Biológicas–CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| |
Collapse
|
39
|
Bhoola KD, Misso NL, Naran A, Thompson PJ. Current status of tissue kallikrein inhibitors: importance in cancer. Curr Opin Investig Drugs 2007; 8:462-8. [PMID: 17621876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The past decade has seen an increase in the understanding of the structure and function of protease inhibitors. The molecular basis of the interaction between a variety of biological substrates or synthetic inhibitors and serine proteases of the kallikrein family has provided insights into inhibitor protein-protease reactive site interactions, which have proved of value in the design of new kallikrein inhibitors. This review focuses on the current understanding of the functional status of kallikrein inhibitors, which include a variety of molecules derived from plant, reptile and mammalian sources, as well as synthetic agents.
Collapse
Affiliation(s)
- Kanti D Bhoola
- Lung Institute of Western Australia and Centre for Asthma, Allergy and Respiratory Research, University of Western Australia, Ground Floor E Block, Sir Charles Gairdner Hospital, Hospital Avenue, Nedlands 6009, Perth, Australia.
| | | | | | | |
Collapse
|
40
|
Abstract
BACKGROUND The human tissue kallikrein gene family, located at chromosome 19q13.4, is the largest contiguous family of proteases in the human genome. The locus encodes all 15 members of the family, 13 of which have been reported as potential biomarkers for several carcinomas and other non-neoplastic diseases. Kallikreins are expressed by a wide range of tissues and implicated in a number of physiological functions, including skin desquamation, semen liquefaction, neural plasticity and the regulation of blood pressure. Kallikrein function is regulated at various levels, including transcription, translation and post-translation. The proteolytic activity of kallikreins is believed to be cascade mediated and may cross-talk with other proteases. These cascades are highly regulated through a series of feedback loops, inhibitors, (auto) degradation and internal cleavage. Uncontrolled proteolytic activity of kallikreins is implicated in a large number of neoplastic and non-neoplastic pathological conditions. CONCLUSIONS As our understanding of their regulatory and functional mechanisms continues to expand, kallikreins are expected to become novel targets for the design of new therapeutics.
Collapse
Affiliation(s)
- Nashmil Emami
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | | |
Collapse
|
41
|
Abstract
Mouse tissue kallikreins (Klks) are members of a large, multigene family consisting of 37 genes, 26 of which can code for functional proteins. Mouse tissue kallikrein 5 (Klk5) has long been thought to be one of these functional genes, but the gene product, mK5, has not been isolated and characterized. In the present study, we prepared active recombinant mK5 using an Escherichia coli expression system, followed by column chromatography. We then determined the biochemical and enzymatic properties of purified mK5. mK5 had trypsin-like activity for Arg at the P1 position, and its activity was inhibited by typical serine protease inhibitors. mK5 degraded gelatin, fibronectin, collagen type IV, high-molecular-weight kininogen, and insulin-like growth factor binding protein-3. Our data suggest that mK5 may be implicated in the process of extracellular matrix remodeling.
Collapse
Affiliation(s)
- Sanath Rajapakse
- Laboratory of Molecular and Cellular Interactions, Faculty of Advanced Life Science, Hokkaido University, Sapporo, Japan
| | | | | | | | | | | | | |
Collapse
|
42
|
Zhang J, Krishnan R, Arnold CS, Mattsson E, Kilpatrick JM, Bantia S, Dehghani A, Boudreaux B, Gupta SN, Kotian PL, Chand P, Babu YS. Discovery of highly potent small molecule kallikrein inhibitors. Med Chem 2007; 2:545-53. [PMID: 17105435 DOI: 10.2174/1573406410602060545] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Uncontrolled kallikrein activation is involved in diseases such as hereditary angioedema, bacterial septic shock and procedures such as cardiopulmonary bypass. Here we report a series of small molecule compounds that potently inhibit kallikrein activity in vitro. Kinetic studies indicate that some of these compounds are slow binding inhibitors of kallikrein with Ki final less than a nanomolar. The ability of these compounds to inhibit the activity of kallikrein was further confirmed in a plasma model by quantitating the release of bradykinin, an endogenous cleavage product of plasma kallikrein. To understand the inhibitory mechanism of the selected compounds toward kallikrein, the interactions between the selected compounds and kallikrein was explored using molecular modeling based on the information of crystal structures of TF/FVIIa and kallikrein. The information presented in the current study provides an initial approach to develop more selective and therapeutically useful small molecule inhibitors.
Collapse
Affiliation(s)
- J Zhang
- Biology Department, BioCryst Pharmaceuticals, Inc. 2190 Parkway Lake Drive, Birmingham, Alabama 35244, USA.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Zhang Y, Ji B, Ling P, Zhang T. Trehalose and hyaluronic acid coordinately stabilized freeze-dried pancreatic kininogenase. Eur J Pharm Biopharm 2007; 65:18-25. [PMID: 16950608 DOI: 10.1016/j.ejpb.2006.07.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2006] [Revised: 07/06/2006] [Accepted: 07/07/2006] [Indexed: 11/26/2022]
Abstract
The ability and mechanisms of stabilization of freeze-dried formulations of pancreatic kininogenase (PKase) by carbohydrates were evaluated. Activity and structure of PKase were examined after freeze-drying and rehydration in presence with or without a carbohydrate. Addition of trehalose, lactose, sucrose, hyaluronic acid (HA) or a combination of trehalose and HA to PKase formulations prior to freeze-drying step increases the stability of PKase during freeze-drying, storage and rehydration as measured by activity preservation. The combination of trehalose and HA is the most effective for the stabilization of PKase. Addition of HA alone to a formulation does not affect protein structure, but it increases glass-transition temperature (Tg) and stability of lyophilized PKase in presence of trehalose during dehydration, storage and rehydration processes. Therefore, trehalose and HA offer complementary properties that improve the stability of PKase during dehydration, storage and rehydration.
Collapse
Affiliation(s)
- Yuhua Zhang
- College of Food Science & Nutritional Engineering, China Agricultural University, Beijing, China
| | | | | | | |
Collapse
|
44
|
Shaw JLV, Grass L, Sotiropoulou G, Diamandis EP. Development of an immunofluorometric assay for human kallikrein 15 (KLK15) and identification of KLK15 in tissues and biological fluids. Clin Biochem 2007; 40:104-10. [PMID: 17045982 DOI: 10.1016/j.clinbiochem.2006.07.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2006] [Revised: 07/19/2006] [Accepted: 07/27/2006] [Indexed: 11/22/2022]
Abstract
BACKGROUND Human kallikrein 15 (KLK15) may have some utility as a prostate, ovarian, and breast cancer biomarker, based on previous studies, which examined mRNA levels of KLK15. The aim of this study was to develop analytical technology for human kallikrein 15, including recombinant protein, specific antibodies, and a sensitive and specific ELISA immunoassay. The assay was then used to examine levels of KLK15 in tissues and biological fluids. METHODS We produced human, recombinant pro-KLK15 in HEK 293 cells. Recombinant KLK15 was purified with various chromatographic steps and used to immunize rabbits and mice for production of KLK15 polyclonal antibodies. We used these antibodies to develop a highly sensitive and specific KLK15 immunoassay and to study KLK15 expression in various tissues and biological fluids. RESULTS Large amounts of pure, recombinant KLK15 have been produced and characterized. KLK15 mouse and rabbit polyclonal antibodies have been employed for development of a KLK15 immunoassay. This assay has a lower detection limit of 0.05 microg/L, and no cross-reactivity with any of the other fourteen kallikreins. Using this assay, KLK15 was detected in prostate, colon, and thyroid tissues, as well as in breast milk and seminal plasma. CONCLUSIONS The KLK15 reagents developed here will allow for analysis of KLK15 protein expression levels in tissues and biological fluids, both normal and cancerous. This will expand upon previously characterized tissue KLK15 mRNA expression studies which suggested that KLK15 might be useful as a biomarker for breast, ovarian, and prostate cancer. KLK15 is another serine protease that is produced in prostate and other tissues and is secreted in seminal plasma and other fluids. Its physiological function needs to be further elucidated.
Collapse
Affiliation(s)
- Julie L V Shaw
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario, Canada, M5G 1X5
| | | | | | | |
Collapse
|
45
|
Oikonomopoulou K, Hansen KK, Saifeddine M, Tea I, Blaber M, Blaber SI, Scarisbrick I, Andrade-Gordon P, Cottrell GS, Bunnett NW, Diamandis EP, Hollenberg MD. Proteinase-activated Receptors, Targets for Kallikrein Signaling. J Biol Chem 2006; 281:32095-112. [PMID: 16885167 DOI: 10.1074/jbc.m513138200] [Citation(s) in RCA: 198] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Serine proteinases like thrombin can signal to cells by the cleavage/activation of proteinase-activated receptors (PARs). Although thrombin is a recognized physiological activator of PAR(1) and PAR(4), the endogenous enzymes responsible for activating PAR(2) in settings other than the gastrointestinal system, where trypsin can activate PAR(2), are unknown. We tested the hypothesis that the human tissue kallikrein (hK) family of proteinases regulates PAR signaling by using the following: 1) a high pressure liquid chromatography (HPLC)-mass spectral analysis of the cleavage products yielded upon incubation of hK5, -6, and -14 with synthetic PAR N-terminal peptide sequences representing the cleavage/activation motifs of PAR(1), PAR(2), and PAR(4); 2) PAR-dependent calcium signaling responses in cells expressing PAR(1), PAR(2), and PAR(4) and in human platelets; 3) a vascular ring vasorelaxation assay; and 4) a PAR(4)-dependent rat and human platelet aggregation assay. We found that hK5, -6, and -14 all yielded PAR peptide cleavage sequences consistent with either receptor activation or inactivation/disarming. Furthermore, hK14 was able to activate PAR(1), PAR(2), and PAR(4) and to disarm/inhibit PAR(1). Although hK5 and -6 were also able to activate PAR(2), they failed to cause PAR(4)-dependent aggregation of rat and human platelets, although hK14 did. Furthermore, the relative potencies and maximum effects of hK14 and -6 to activate PAR(2)-mediated calcium signaling differed. Our data indicate that in physiological settings, hKs may represent important endogenous regulators of the PARs and that different hKs can have differential actions on PAR(1), PAR(2), and PAR(4).
Collapse
MESH Headings
- Amino Acid Sequence
- Animals
- Animals, Genetically Modified
- Aorta, Thoracic/drug effects
- Baculoviridae/genetics
- Blood Platelets/metabolism
- Calcium Signaling/drug effects
- Cell Line
- Chromatography, High Pressure Liquid
- Dose-Response Relationship, Drug
- Epithelial Cells/drug effects
- Humans
- Kallikreins/chemical synthesis
- Kallikreins/chemistry
- Kallikreins/classification
- Kallikreins/pharmacology
- Male
- Mass Spectrometry
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Molecular Sequence Data
- Muscle Relaxation/drug effects
- Muscle, Smooth, Vascular/drug effects
- Platelet Aggregation/drug effects
- Rats
- Rats, Sprague-Dawley
- Receptors, Proteinase-Activated/chemistry
- Receptors, Proteinase-Activated/drug effects
- Receptors, Proteinase-Activated/genetics
- Receptors, Proteinase-Activated/physiology
- Recombinant Proteins/chemistry
- Recombinant Proteins/pharmacology
- Signal Transduction/drug effects
- Swine
- Thrombin/pharmacology
- Trypsin/pharmacology
Collapse
Affiliation(s)
- Katerina Oikonomopoulou
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario M5G 1L5, Canada
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Luo LY, Soosaipillai A, Grass L, Diamandis EP. Characterization of human kallikreins 6 and 10 in ascites fluid from ovarian cancer patients. Tumour Biol 2006; 27:227-34. [PMID: 16864975 DOI: 10.1159/000094693] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2006] [Accepted: 04/21/2006] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES Human kallikreins 6 (hK6) and 10 (hK10) are secreted serine proteases. We previously found that hK6 and hK10 are highly overexpressed in epithelial ovarian tumors and demonstrated that serum levels of hK6 and hK10 are valuable biomarkers for ovarian cancer diagnosis and prognosis. Our aim is to purify and characterize these two kallikreins from ascites fluid of ovarian cancer patients. METHODS Protein concentrations of hK6 and hK10 in ovarian cancer ascites fluids were measured with ELISA-type immunoassays. hK6 and hK10 were purified from the ascites fluids with immunoaffinity columns, followed by reverse-phase high performance liquid chromatography. Purified hK6 and hK10 were then subjected to N-terminal sequencing. Enzymatic analyses were performed with synthetic fluorogenic peptides. RESULTS hK6 and hK10 were present in ovarian cancer ascites fluid at concentrations ranging from 0.2-571 and 0.7-220 microg/l, respectively. The majority of hK6 and hK10 in the ascites fluids were present in the free (uncomplexed) form. Both hK6 and hK10 purified from the ascites fluid were zymogens with a molecular mass of 30 kDa. Purified hK6 exhibited trypsin-like enzymatic activity, whereas no enzymatic activity was observed for purified hK10. The enzymatic activity of hK6 could be suppressed by a neutralizing monoclonal antibody. CONCLUSIONS The majority of hK6 secreted by the ovarian tumor cells into the ascites fluid are present in the uncomplexed, zymogen form, possessing weak trypsin-like enzymatic activity. All hK10 present in ovarian cancer ascites fluids are in the uncomplexed, zymogen form and have no detectable enzymatic activity.
Collapse
Affiliation(s)
- Liu-Ying Luo
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Canada
| | | | | | | |
Collapse
|
47
|
Beaufort N, Debela M, Creutzburg S, Kellermann J, Bode W, Schmitt M, Pidard D, Magdolen V. Interplay of human tissue kallikrein 4 (hK4) with the plasminogen activation system: hK4 regulates the structure and functions of the urokinase-type plasminogen activator receptor (uPAR). Biol Chem 2006; 387:217-22. [PMID: 16497155 DOI: 10.1515/bc.2006.029] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The plasminogen activation system is involved in cancer progression and metastasis. Among other proteolytic factors, it includes the serine protease urokinase-type plasminogen activator (uPA) and its three-domain (D1D2D3) receptor uPAR (CD87), which focuses plasminogen activation to the cell surface. The function of uPAR is regulated in part through shedding of domain D1 by proteases, e.g., uPA itself or plasmin. Human tissue kallikrein 4 (hK4), which is highly expressed in prostate and ovarian tumor tissue, was previously shown to cleave and activate the pro-enzyme forms of prostate-specific antigen (PSA, tissue kallikrein hK3) and uPA. Here we demonstrate that uPAR is also a target for hK4, being cleaved in the D1-D2 linker sequence and, to a lesser extent, in its D3 juxtamembrane domain. hK4 may thus modulate the tumor-associated uPA/uPAR-system activity by either activating the pro-enzyme form of uPA or cleaving the cell surface-associated uPA receptor.
Collapse
Affiliation(s)
- Nathalie Beaufort
- Unité de Défense Innée et Inflammation/INSERM E0336, Département de Médecine Moléculaire, Institut Pasteur, F-75015 Paris, France
| | | | | | | | | | | | | | | |
Collapse
|
48
|
Marangoni RA, Carmona AK, Passaglia RCAT, Nigro D, Fortes ZB, de Carvalho MHC. Role of the kallikrein-kinin system in Ang-(1-7)-induced vasodilation in mesenteric arterioles of Wistar rats studied in vivo-in situ. Peptides 2006; 27:1770-5. [PMID: 16595159 DOI: 10.1016/j.peptides.2006.02.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2005] [Revised: 02/01/2006] [Accepted: 02/03/2006] [Indexed: 11/17/2022]
Abstract
Angiotensin-(1-7) [Ang-(1-7)], exerts a variety of actions in the cardiovascular system, with an important effect being vasodilation. In this work, we investigated the relationship between the vasodilatory activity of Ang-(1-7) and the kallikrein-kinin system. Intravital microscopy was used to study the vasodilation caused by Ang-(1-7) in the mesenteric vascular bed of anesthetized Wistar rats. The topical application of Ang-(1-7) caused vasodilation of mesenteric arterioles that was reduced by A-779, JE 049 and peptidase inhibitors (aprotinin, SBTI, PKSI 527, E-64, PMSF). These results indicated that the vasodilation induced by Ang-(1-7) in the mesenteric arterioles of Wistar rats was heavily dependent on the activation of kallikrein and subsequent kinin formation.
Collapse
Affiliation(s)
- Rossana Anderson Marangoni
- Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo (USP), Av. Prof. Lineu Prestes 1524, Cidade Universitária, 05508-900 São Paulo, SP, Brazil
| | | | | | | | | | | |
Collapse
|
49
|
Michael IP, Pampalakis G, Mikolajczyk SD, Malm J, Sotiropoulou G, Diamandis EP. Human tissue kallikrein 5 is a member of a proteolytic cascade pathway involved in seminal clot liquefaction and potentially in prostate cancer progression. J Biol Chem 2006; 281:12743-50. [PMID: 16517595 DOI: 10.1074/jbc.m600326200] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human tissue kallikreins (hKs) are a family of fifteen serine proteases. Several lines of evidence suggest that hKs participate in proteolytic cascade pathways. Human kallikrein 5 (hK5) has trypsin-like activity, is able to self-activate, and is co-expressed in various tissues with other hKs. In this study, we examined the ability of hK5 to activate other hKs. By using synthetic heptapeptides that encompass the activation site of each kallikrein and recombinant pro-hKs, we demonstrated that hK5 is able to activate pro-hK2 and pro-hK3. We then showed that, following their activation, hK5 can internally cleave and deactivate hK2 and hK3. Given the predominant expression of hK2 and hK3 in the prostate, we examined the pathophysiological role of hK5 in this tissue. We studied the regulation of hK5 activity by cations (Zn2+, Ca2+, Mg2+, Na2+, and K+) and citrate and showed that Zn can efficiently inhibit hK5 activity at levels well below its normal concentration in the prostate. We also show that hK5 can degrade semenogelins I and II, the major components of the seminal clot. Semenogelins can reverse the inhibition of hK5 by Zn2+, providing a novel regulatory mechanism of its serine protease activity. hK5 is also able to internally cleave insulin-like growth factor-binding proteins 1, 2, 3, 4, and 5, but not 6, suggesting that it might be involved in prostate cancer progression through growth factor regulation. Our results uncover a kallikrein proteolytic cascade pathway in the prostate that participates in seminal clot liquefaction and probably in prostate cancer progression.
Collapse
Affiliation(s)
- Iacovos P Michael
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada
| | | | | | | | | | | |
Collapse
|
50
|
Angelo PF, Lima AR, Alves FM, Blaber SI, Scarisbrick IA, Blaber M, Juliano L, Juliano MA. Substrate specificity of human kallikrein 6: salt and glycosaminoglycan activation effects. J Biol Chem 2006; 281:3116-26. [PMID: 16321973 DOI: 10.1074/jbc.m510096200] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human kallikrein 6 (hK6) is abundantly expressed in the central nervous system and is implicated in demyelinating disease. This study provided biochemical data about the substrate specificity and activation of hK6 by glycosaminoglycans and by kosmotropic salts, which followed the Hofmeister series. The screening of fluorescence resonance energy transfer (FRET) peptide families derived from Abz-KLRSSKQ-EDDnp resulted in the finding that Abz-AFRFSQ-EDDnp (where Abz is ortho-aminobenzoic acid and EDDnp is N-[2,4-dinitrophenyl]ethylenediamine)) is the best synthetic substrate described so far for hK6 (kcat/Km 38,667 s(-1) mm(-1)). It is noteworthy that the AFRFS sequence was found as a motif in the amino-terminal domain of seven human ionotropic glutamate receptor subunits. We also examined the hK6 hydrolytic activity on FRET peptides derived from human myelin basic protein, precursor of the Abeta amyloid peptide, reactive center loop of alpha1-antichymotrypsin, plasminogen, and maturation and inactivation cleavage sites of hK6, which were described earlier as natural substrates for hK6. The best substrates were derived from myelin basic protein. The hK6 maturation cleavage site was poorly hydrolyzed, and no evidence was found to support a two-step self-activation process reported previously. Finally, we assayed FRET peptides derived from sequences that span the cleavage sites for activation of protease-activated receptors (PAR) 1-4, and only the substrate with the PAR 2 sequence was hydrolyzed. These results further supported the hypothesis that hK6 expressed in the central nervous system is involved in normal myelin turnover/demyelination processes, but it is unlikely to self-activate. This report also suggested the possible modulation of ionotropic glutamate receptors and activation of PAR 2 by hK6.
Collapse
Affiliation(s)
- Pedro Francisco Angelo
- Department of Biophysics, Escola Paulista de Medicina, Universidade Federal de São Paulo, Rua Três de Maio 100, 04044-20 São Paulo, Brazil
| | | | | | | | | | | | | | | |
Collapse
|