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Dunaevsky YE, Tereshchenkova VF, Oppert B, Belozersky MA, Filippova IY, Elpidina EN. Human proline specific peptidases: A comprehensive analysis. Biochim Biophys Acta Gen Subj 2020; 1864:129636. [DOI: 10.1016/j.bbagen.2020.129636] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 05/05/2020] [Accepted: 05/14/2020] [Indexed: 02/07/2023]
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Gandhi D, Chanalia P, Attri P, Dhanda S. Dipeptidyl peptidase-II from probiotic Pediococcus acidilactici: Purification and functional characterization. Int J Biol Macromol 2016; 93:919-932. [PMID: 27640091 DOI: 10.1016/j.ijbiomac.2016.09.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 09/04/2016] [Accepted: 09/07/2016] [Indexed: 11/27/2022]
Abstract
Dipeptidylpeptidase-II (DPP-II, E.C. 3.4.14.2), an exopeptidase was purified 15.4 fold with specific activity and yield of 15.4U/mg/mL and 14.68% respectively by a simple two step procedure from a probiotic Pediococcus acidilactici. DPP-II is 38.7KDa homodimeric serine peptidase with involvement of His and subunit mass of 18.9KDa. The enzyme exhibited optimal activity at pH 7.0 and 37°C with activation energy of 24.97kJ/mol. The enzyme retained more than 90% activity upto 50°C thus adding industrial importance. DPP-II hydrolysed Lys-Ala-4mβNA with KM of 50μM and Vmax of 30.8nmol/mL/min. In-silico characterization studies of DPP-II on the basis of peptide fragments obtained by MALDI-TOF revealed an evolutionary relationship between DPP-II of prokaryotes and phosphate binding proteins. Secondary and three-dimensional structure of enzyme was also deduced by in-silico approach. Functional studies of DPP-II by TLC and HPLC-analysis of collagen degraded products revealed that enzyme action released free amino acids and other metabolites. Microscopic and SDS-PAGE analysis of enzyme treated analysis of chicken's chest muscle (meat) hydrolysis revealed change and hydrolysis of myofibrils. This may affect the flavor and texture of meat thereby suggesting its role in meat tenderization. Being a protein of LAB (Lactic acid bacteria), it is also expected to be safe.
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Affiliation(s)
- Dimpi Gandhi
- Department of Biochemistry, Kurukshetra University, Kurukshetra, India.
| | - Preeti Chanalia
- Department of Biochemistry, Kurukshetra University, Kurukshetra, India.
| | - Pooja Attri
- Department of Biochemistry, Kurukshetra University, Kurukshetra, India.
| | - Suman Dhanda
- Department of Biochemistry, Kurukshetra University, Kurukshetra, India.
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Khaket TP, Dhanda S, Jodha D, Singh J. Purification and biochemical characterization of dipeptidyl peptidase-II (DPP7) homologue from germinated Vigna radiata seeds. Bioorg Chem 2015; 63:132-41. [PMID: 26524724 DOI: 10.1016/j.bioorg.2015.10.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 10/06/2015] [Accepted: 10/12/2015] [Indexed: 11/25/2022]
Abstract
Dipeptidyl peptidases (DPPs) are potent exopeptidases, which possess central role in proteolysis. As compared to other members of DPP family, proline containing dipeptide hydrolysing activity of DPP-II (Dipeptidyl peptidase II) is unique as it hydrolyses imino group and plays a key role in protein metabolism. In present study, DPP-II was purified from germinated moong bean seeds using acid and ammonium sulphate precipitation followed by successive chromatographies on gel filtration (pH 7.4) and cation exchanger (pH 5.9). Native PAGE and in-situ gel assay confirmed the apparent homogeneity. Purified plant DPP-II is an oligomeric enzyme with molecular weight of 97.3kDa. Highest DPP-II activity was observed at pH 7.5 and 37°C, with stability in the range of neutral to alkaline pH. Substrate specificity showed consequent activity for proline containing dipeptide followed by Lys-Ala and other hydrophobic dipeptides, but none of the studied endopeptidase and monopeptidase substrate was hydrolysed. Catalytic characterization with modifier studies revealed the involvement of Ser and His residues in its catalytic mechanism. Its dipeptidyl peptidase activity for proline containing dipeptide supported its role in the bioactive peptide generation and food industry. Functional studies of DPP-II revealed the significant involvement of this glycoproteinous enzyme in protein mobilization during germination. Further studies on industrial applications exploring physiological role are in progress.
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Affiliation(s)
- Tejinder Pal Khaket
- Department of Biochemistry, Kurukshetra University, Kurukshetra, Haryana, India; Department of Biotechnology, Maharishi Markandeshwar University, Ambala, Haryana, India
| | - Suman Dhanda
- Department of Biochemistry, Kurukshetra University, Kurukshetra, Haryana, India
| | - Druksakshi Jodha
- Department of Biochemistry, Kurukshetra University, Kurukshetra, Haryana, India
| | - Jasbir Singh
- Department of Biochemistry, Kurukshetra University, Kurukshetra, Haryana, India.
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Maes MB, Scharpé S, De Meester I. Dipeptidyl peptidase II (DPPII), a review. Clin Chim Acta 2007; 380:31-49. [PMID: 17328877 DOI: 10.1016/j.cca.2007.01.024] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2006] [Revised: 01/17/2007] [Accepted: 01/21/2007] [Indexed: 11/20/2022]
Abstract
An increasing number of biological processes appear to be regulated by Pro-specific N-terminal processing. The proline-specific dipeptidyl peptidases (DPPs) like DPPIV, fibroblast activation protein alpha (FAP), DPPII, DPP8 and DPP9, because of their preference for cleavage after X-Pro in vitro, are likely to be involved in many of these processes. These DPPs are emerging as an important protease family with roles in the regulation of signaling by peptide hormones. Dipeptidyl peptidase II (DPPII, E.C. 3.4.14.2) is an intracellular protease that localizes to the vesicular system. It releases, preferably at acidic pH, N-terminal dipeptides from oligopeptides with Pro or Ala in the penultimate position. Despite the fact that the physiological role of DPPII still has not been elucidated, several suggestions were made on possible functions of the enzyme depending on its localization in different cells, body fluids and organs. DPPII was a.o. suggested to be involved in the processes of cell differentiation and in the protection from cell death, and to have a role in the degradation of collagen fragments, myofibrillar proteins and short neuropeptides. Moreover, changes in the level and distribution of the enzyme provided clues indicating additional roles in disease-related processes. Here we review the DPPII literature, aiming to bring more clarity in the disperse data on this subject and give a state of the art on DPPII research.
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Affiliation(s)
- Marie-Berthe Maes
- Laboratory for Medical Biochemistry, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium
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Maes MB, Martinet W, Schrijvers DM, Van der Veken P, De Meyer GRY, Augustyns K, Lambeir AM, Scharpé S, De Meester I. Dipeptidyl peptidase II and leukocyte cell death. Biochem Pharmacol 2006; 72:70-9. [PMID: 16725115 DOI: 10.1016/j.bcp.2006.04.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Revised: 03/20/2006] [Accepted: 04/07/2006] [Indexed: 11/30/2022]
Abstract
Dipeptidyl peptidase (DPP) II (E.C. 3.4.14.2) is an intracellular protease that releases, preferably at acidic pH, N-terminal dipeptides from oligopeptides with Pro or Ala in the penultimate position. The natural substrates and the physiological role of DPPII remain unclear. The aim of the present study was to investigate the involvement of DPPII activity in different forms of cell death (apoptosis, necrosis and autophagy) in human leukocytes. We determined specific DPP activities in leukocytes. Compared to other subpopulations of peripheral blood mononuclear cells (PBMC), we observed relatively high DPPII specific activity in monocytic cells, opening new perspectives for further investigation of the DPPII functions. A second intriguing finding was that DPPII specific activity increased during necrosis, whereas induction of apoptosis or autophagy did not affect any of the dipeptidyl peptidase activities. Finally, we showed that inhibition of DPPII (>90%) using the in vitro applicable, highly potent (K(i) of 0.082+/-0.048 nM) and selective DPPII inhibitor UAMC00039, did not induce any form of cell death in leukocytes. These data are of importance for a more precise interpretation of the in vitro and in vivo effects of other dipeptidyl peptidase inhibitors.
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Affiliation(s)
- Marie-Berthe Maes
- Laboratory of Medical Biochemistry, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
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6
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ADRF Research Grant Abstracts. Aust Dent J 2005. [DOI: 10.1111/j.1834-7819.2005.tb00377.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Mabuchi R, Matsuzaka K, Shimono M. Cell proliferation and cell death in periodontal ligaments during orthodontic tooth movement. J Periodontal Res 2002; 37:118-24. [PMID: 12009181 DOI: 10.1034/j.1600-0765.2001.10602.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The purpose of this study was to investigate cellular responses of periodontal ligaments during tooth movement. Twenty-eight male Sprague-Dawley rats, weighing 200-250 g each, were used. To create the orthodontic force, elastic rubber blocks (0.65 mm thick) were inserted between the maxillary first and second molars on both sides. On days 3, 7, 10, 14, 21 and 28 after rubber block insertion, histopathological changes in both the tension and the pressure sides were examined by immunohistochemistry using proliferating cell nuclear antigen (PCNA) and by the TUNEL method. The ratios of PCNA-positive cells on the tension side 3 and 7 days after rubber block insertion were higher than those on the pressure side. The ratios of PCNA-positive cells on the tension side were highest at day 3 after insertion and then decreased during the remainder of the experimental period. On the pressure side, the ratios of PCNA-positive cells increased up to day 10 post insertion, then decreased from 14 to 28 days. The ratios of TUNEL-positive cells on both the tension and the pressure sides increased throughout the entire experimental period. These results indicate that the periodontal ligaments on the tension side are able to respond more promptly to orthodontic forces than those on the pressure side. The data also suggest that the ratios of cell proliferation and of cell death are closely related to the regeneration and reconstruction of periodontal ligaments which reflect the orthodontic force.
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Affiliation(s)
- R Mabuchi
- Department of Pathology, Tokyo Dental College, Chiba, Japan
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Smid JR, Young WG, Monsour PA. Dipeptidyl-peptidase II and cathepsin B activities in amelogenesis of the rat incisor. Eur J Oral Sci 2001; 109:260-6. [PMID: 11531072 DOI: 10.1034/j.1600-0722.2001.00025.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A body of published evidence suggests that a significant portion of enamel matrix protein synthesized by ameloblasts localises in the lysosomal-endosomal organelles of these enamel organ cells. Little is known regarding the lysosomal proteolytic activities during amelogenesis. The aims of this study were to detect and measure the activities of lysosomal peptidases cathepsin B (E.C. 3.4.22.1) and dipeptidyl-peptidase II (E.C. 3.4.14.2) in the enamel organ of the rat incisor and to ascertain whether rat enamel matrix proteins are degraded by these peptidases in vitro. Whole enamel organs were dissected from rat mandibular incisors. Enamel protein was also collected from the rat teeth. Analysis indicated that the rat incisor enamel organs contained specific activities of both dipeptidyl-peptidase II and cathepsin B at levels comparable with those of kidney which is rich in both these lysosomal peptidases. Gel electrophoresis and immunoblotting demonstrated that both cathepsin B and dipeptidyl-peptidase II were able to substantially degrade the rat enamel proteins in vitro. Based on these observations, we propose that lysosomal proteases have roles in amelogenesis in the intracellular degradation of amelogenins.
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Affiliation(s)
- J R Smid
- Oral Biology and Pathology, School of Dentistry, The University of Queensland, Brisbane, Australia.
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Kondo S, Tamura Y, Bawden JW, Tanase S. The immunohistochemical localization of Bax and Bcl-2 and their relation to apoptosis during amelogenesis in developing rat molars. Arch Oral Biol 2001; 46:557-68. [PMID: 11311203 DOI: 10.1016/s0003-9969(00)00139-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Bax and Bcl-2 are members of a family of intracellular, membrane-associated proteins that regulate programmed cell death. It has been suggested that, when Bax predominates, programmed cell death is accelerated and the apoptosis inhibitory activity of Bcl-2 is suppressed. The present study was undertaken to immunohistochemically (IHC) localize Bax and Bcl-2 in the cells of the enamel organ during amelogenesis in rat molars. Also, apoptotic cells were detected by TUNEL staining. The IHC intense localization of Bcl-2 and light staining for Bax in the pre-ameloblasts suggest that apoptosis is inhibited in the proliferating pre-ameloblasts. This is consistent with an absence of TUNEL staining for apoptosis in these cells. However, in the late secretory and transition ameloblasts, and adjacent stratum intermedium, evidence of apoptosis of the ameloblasts was observed. Bax and Bcl-2 were co-localized in the proximal ends of late secretory, transition and early maturation-stage ameloblasts, but immunoreactivity for Bax markedly increased in the proximal ends of late secretory and transition ameloblasts, while the Bcl-2 staining appeared to be lighter. This suggests that Bax antagonized Bcl-2 function, limiting the ability of Bcl-2 to prolong cell survival. In the early maturation stage, Bax staining faded while the immunoreactivity for Bcl-2 increased. Evidence of distinct apoptosis was reduced in the early maturation stage ameloblasts. When related to the occurrence of apoptosis during amelogenesis, the relative intensity of expression of Bax and Bcl-2 changed in a pattern consistent with that observed in other cell lines. This indicates that these proteins play essential roles in the process of amelogenesis, as predicted by their proposed mechanisms of action in the control of apoptosis.
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Affiliation(s)
- S Kondo
- The Department of Pediatric Dentistry, Asahi University School of Dentistry, 1851-1 501-0296, Hozumi Motosu Gifu, Japan
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Fukasawa KM, Fukasawa K, Higaki K, Shiina N, Ohno M, Ito S, Otogoto J, Ota N. Cloning and functional expression of rat kidney dipeptidyl peptidase II. Biochem J 2001; 353:283-90. [PMID: 11139392 PMCID: PMC1221570 DOI: 10.1042/0264-6021:3530283] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Dipeptidyl peptidase II (DPP II; EC 3.4.14.2) from rat kidney was purified to a specific activity of 65.4 micromol/min per mg of protein for Lys-Ala-beta-naphthylamide. The N-terminal and partial amino acid sequences of the enzyme were determined. The peptide sequences were used to identify expressed sequence tag (EST) clones. By using the cDNA fragment of one of the EST clones as a probe, we isolated a cDNA clone with 1710 bp encoding DPP II from a rat kidney cDNA library. The cDNA of rat DPP II contained an open reading frame of 1500 bp, coding for a protein of 500 amino acids. The first 10 residues of the purified enzyme matched the deduced protein sequence starting with residue 37, suggesting the presence of a signal peptide. The mature enzyme (464 residues) had a calculated molecular mass of 51400 Da, which was lower than the value (about 60000 Da) determined by SDS/PAGE; and the deduced amino acid sequence showed six potential N-glycosylation sites. The deduced amino acid sequence of rat DPP II shared high similarity with quiescent-cell proline dipeptidase (78% identity) and prolyl carboxypeptidase (38% identity) and bore the putative catalytic triad (Ser, Asp, His) conserved in serine peptidase families. We transiently transfected COS-7 cells with pcDNA3.1 containing the cloned cDNA and obtained the overexpression of an immunoreactive protein (of about 60000 Da). The transfected cells showed Lys-Ala-methylcoumarinamide-hydrolysing activity that was 50 times higher than the control cells.
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Affiliation(s)
- K M Fukasawa
- Department of Oral Biochemistry, Matsumoto Dental University, Shiojiri, Nagano 399-0781, Japan.
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Nanci A, Mocetti P, Sakamoto Y, Kunikata M, Lozupone E, Bonucci E. Morphological and immunocytochemical analyses on the effects of diet-induced hypocalcemia on enamel maturation in the rat incisor. J Histochem Cytochem 2000; 48:1043-58. [PMID: 10898799 DOI: 10.1177/002215540004800803] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
During the maturation stage of amelogenesis, the loss of matrix proteins combined with an accentuated but regulated influx of calcium and phosphate ions into the enamel layer results in the "hardest" tissue of the body. The aim of the present investigation was to examine the effects of chronic hypocalcemia on the maturation of enamel. Twenty-one-day old male Wistar rats were given a calcium-free diet and deionized water for 28 days, while control animals received a normal chow. The rats were perfused with aldehyde and the mandibular incisors were processed for histochemical and ultrastructural analyses and for postembedding colloidal gold immunolabeling with antibodies to amelogenin, ameloblastin, and albumin. The maturation stage enamel organ in hypocalcemic rats exhibited areas with an apparent increase in cell number and the presence of cyst-like structures. In both cases the cells expressed signals for ameloblastin and amelogenin. The content of the cysts was periodic acid-Schiff- and periodic acid-silver nitrate-methanamine-positive and immunolabeled for amelogenin, ameloblastin, and albumin. Masses of a similar material were also found at the enamel surface in depressions of the ameloblast layer. In addition, there were accumulations of glycoproteinaceous matrix at the interface between ameloblasts and enamel. In decalcified specimens, the superficial portion of the enamel matrix sometimes exhibited the presence of tubular crystal "ghosts." The basal lamina, normally separating ameloblasts and enamel during the maturation stage, was missing in some areas. Enamel crystals extended within membrane invaginations at the apical surface of ameloblasts in these areas. Immunolabeling for amelogenin, ameloblastin, and albumin over enamel was variable and showed a heterogeneous distribution. In contrast, enamel in control rats exhibited a homogeneous labeling for amelogenin, a concentration of ameloblastin at the surface, and weak reactivity for albumin. These results suggest that diet-induced chronic hypocalcemia interferes with both cellular and extracellular events during enamel maturation.
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Affiliation(s)
- A Nanci
- Faculté de Médecine Dentaire, Université de Montréal, Montréal, QC, Canada.
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Yamamoto S, Sawada K, Shimomura H, Kawamura K, James TN. On the nature of cell death during remodeling of hypertrophied human myocardium. J Mol Cell Cardiol 2000; 32:161-75. [PMID: 10652200 DOI: 10.1006/jmcc.1999.1064] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cardiocyte loss during myocardial hypertrophy leads to progressive dysfunction in human hearts with chronic hemodynamic overload. The mechanism for such cell elimination is unknown. We examined lysosomal participation in cardiocytic degradation present in human cardiac biopsies, utilizing electron microscopic cytochemistry (acid phosphatase). Lysosomes were significantly increased in number (t-test, P<0.001) in 50 hemodynamically overloaded hearts (375+/-69, mean+/-s.e.m., per 5,000 microm(2) cardiocytic area; eight controls, 38+/-11). Secondary lysosomes were prominent near degenerative intracellular organelles in both hypertrophic and atrophic cardiocytes. Increased lysosomal and phagocytic activity in the cytoplasm without typical nuclear apoptosis resembled cytoplasmic degradation in developmental programmed cell death described in different tissues. We also demonstrated cardiocytic DNA degradation (in situ nick-end labeling) in autopsy hearts, including 299 nuclei normalized per 10(6) observed nuclei from five concentrically hypertrophied hearts, 1961 nuclei from five eccentrically hypertrophied hearts, and no positive nuclei in five controls. We postulate a chronic self-controlled cytoplasmic proteolysis in cardiocytes, not initially associated with either nuclear degradation or intercellular dehiscence but later possibly accompanied by apoptotic nuclear elimination, and leading to apoptotic cell death.
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Affiliation(s)
- S Yamamoto
- Department of Medicine and Department of Pathology, at the University of Texas Medical Branch, Galveston, Texas 77555-0175, USA
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Abstract
Proline is unique among the 20 amino acids due to its cyclic structure. This specific conformation imposes many restrictions on the structural aspects of peptides and proteins and confers particular biological properties upon a wide range of physiologically important biomolecules. In order to adequately deal with such peptides, nature has developed a group of enzymes that recognise this residue specifically. These peptidases cover practically all situations where a proline residue might occur in a potential substrate. In this paper we endeavour to discuss these enzymes, particularly those responsible for peptide or protein hydrolysis at proline sites. We have detailed their discovery, biochemical attributes and substrate specificities and have provided information as to the methodology used to detect and manipulate their activities. We have also described the roles, or potential roles that these enzymes may play physiologically and the consequences of their dysfunction in varied disease states.
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Affiliation(s)
- D F Cunningham
- School of Biological Sciences, Dublin City University, Dublin, Ireland
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Nishikawa S, Sasaki F. DNA localization in nuclear fragments of apoptotic ameloblasts using anti-DNA immunoelectron microscopy: programmed cell death of ameloblasts. Histochem Cell Biol 1995; 104:151-9. [PMID: 8536072 DOI: 10.1007/bf01451574] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Ameloblasts responsible for tooth enamel formation are classified into two different phases: secretion and maturation. At the transition between these secretion and maturation stages, a considerable number of cells die. In this study, we examined the morphology of degenerating ameloblasts by conventional electron microscopy, and DNA cleavage in degenerating ameloblast nuclei by the in situ terminal transferase assay. The results suggest that apoptosis (programmed cell death) in ameloblasts, including DNA ligation is induced at the transitional stage. The nuclear fragments, chromatin condensation and DNA relocation in apoptotic nuclei were examined quantitatively by post-embedding anti-DNA immunogold electron microscopy and the in situ terminal transferase assay combined with electron microscopy. Numerical analysis revealed that immunogold labeling density in the condensed chromatin of apoptotic nuclei was comparable on the average to that in the perinuclear heterochromatin of normal nuclei, and that individual apoptotic nuclear fragments exhibited highly variable to that of normal heterochromatin, to fragments with densities twice as high as that of normal heterochromatin. The in situ terminal transferase assay combined with electron microscopy detected DNA ends exposed by ultrathin sectioning as well as DNA cleavage by a putative endonuclease. In conclusion, the state of the DNA, including its ligation and degeneration, changes gradually during chromatin condensation and nuclear fragmentation of apoptosis.
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Affiliation(s)
- S Nishikawa
- Department of Biology, Tsurumi University, School of Dental Medicine, Yokohama, Japan
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