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Matić A, Šupljika F, Brkić H, Jurasović J, Karačić Z, Tomić S. Identification of an Additional Metal-Binding Site in Human Dipeptidyl Peptidase III. Int J Mol Sci 2023; 24:12747. [PMID: 37628928 PMCID: PMC10454320 DOI: 10.3390/ijms241612747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 08/03/2023] [Accepted: 08/11/2023] [Indexed: 08/27/2023] Open
Abstract
Dipeptidyl peptidase III (DPP III, EC 3.4.14.4) is a monozinc metalloexopeptidase that hydrolyzes dipeptides from the N-terminus of peptides consisting of three or more amino acids. Recently, DPP III has attracted great interest from scientists, and numerous studies have been conducted showing that it is involved in the regulation of various physiological processes. Since it is the only metalloenzyme among the dipeptidyl peptidases, we considered it important to study the process of binding and exchange of physiologically relevant metal dications in DPP III. Using fluorimetry, we measured the Kd values for the binding of Zn2+, Cu2+, and Co2+ to the catalytic site, and using isothermal titration calorimetry (ITC), we measured the Kd values for the binding of these metals to an additional binding site. The structure of the catalytic metal's binding site is known from previous studies, and in this work, the affinities for this site were calculated for Zn2+, Cu2+, Co2+, and Mn2+ using the QM approach. The structures of the additional binding sites for the Zn2+ and Cu2+ were also identified, and MD simulations showed that two Cu2+ ions bound to the catalytic and inhibitory sites exchanged less frequently than the Zn2+ ions bound to these sites.
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Affiliation(s)
- Antonia Matić
- Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia;
| | - Filip Šupljika
- Department of Chemistry and Biochemistry, Faculty of Food Technology and Biotechnology, Pierottijeva 6, 10000 Zagreb, Croatia;
| | - Hrvoje Brkić
- Faculty of Medicine, J. J. Strossmayer University of Osijek, 31000 Osijek, Croatia;
- Faculty of Dental Medicine and Health, J. J. Strossmayer University of Osijek, 31000 Osijek, Croatia
| | - Jasna Jurasović
- Analytical Toxicology and Mineral Metabolism Unit, Institute for Medical Research and Occupational Health, 10000 Zagreb, Croatia;
| | - Zrinka Karačić
- Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia;
| | - Sanja Tomić
- Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia;
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Lo SY, Goulet DL, Fraaz U, Siemann S. Effect of pH and denaturants on the fold and metal status of anthrax lethal factor. Arch Biochem Biophys 2020; 692:108547. [PMID: 32828796 DOI: 10.1016/j.abb.2020.108547] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 08/02/2020] [Accepted: 08/17/2020] [Indexed: 01/26/2023]
Abstract
Anthrax lethal factor (LF) is a critical component of the anthrax toxin, and functions intracellularly as a zinc-dependent endopeptidase targeting proteins involved in maintaining critical host signaling pathways. To reach the cytoplasm, LF requires to be unfolded and guided through the narrow protective antigen pore in a pH-dependent process. The current study sought to address the question as to whether LF is capable of retaining its metal ion when exposed to a low-pH environment (similar to that found in late endosomes) and an unfolding stress (induced by urea). Using a combination of tryptophan fluorescence spectroscopy and chelation studies, we show that a decrease in the pH value (from 7.0 to 5.0) leads to a pronounced shift in the onset of structural alterations in LF to lower urea concentrations. More importantly, the enzyme was found to retain its Zn2+ ion beyond the unfolding transitions monitored by Trp fluorescence, a finding indicative of tight metal binding to LF in a non-native state. In addition, an analysis of red-edge excitation shift (REES) spectra suggests the protein to maintain residual structure (a feature necessary for metal binding) even at very high denaturant concentrations. Furthermore, studies using the chromophoric chelator 4-(2-pyridylazo)resorcinol (PAR) revealed LF's Zn2+ ion to become accessible to complexation at urea concentrations in between those required to cause structural changes and metal dissociation. This phenomenon likely originates from the conversion of a PAR-inaccessible (closed) to a PAR-accessible (open) state of LF at intermediate denaturant concentrations.
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Affiliation(s)
- Suet Y Lo
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, P3E 2C6, Canada
| | - Danica L Goulet
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, P3E 2C6, Canada
| | - Usama Fraaz
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, P3E 2C6, Canada
| | - Stefan Siemann
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, P3E 2C6, Canada.
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Goulet DL, Fraaz U, Zulich CJ, Pilkington TJ, Siemann S. Specificity-directed design of a FRET-quenched heptapeptide for assaying thermolysin-like proteases. Anal Biochem 2020; 604:113826. [PMID: 32622975 DOI: 10.1016/j.ab.2020.113826] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 06/08/2020] [Indexed: 11/18/2022]
Abstract
Thermolysin (TL) is an industrially important zinc endopeptidase, and the prototype of the M4 family of metallopeptidases. The catalytic function of TL and its relatives is typically assessed using chromogenic or more sensitive fluorescent peptides, with the latter substrates relying on Förster resonance energy transfer (FRET). Here, we demonstrate that a FRET-quenched heptapeptide designed on the basis of the enzyme's substrate specificity (Dabcyl-FKFLGKE-EDANS) is efficiently cleaved by TL and dispase (a TL-like protease) in between the Phe3 and Leu4 residues. The specificity constants (determined at pH 7.4 and 25 °C) for TL and dispase (3.6 × 106 M-1 s-1 and 4.6 × 106 M-1 s-1, respectively) were found to be amongst the highest documented for any TL substrate. Maximal peptide cleavage rates were achieved at pH 6.5 and a temperature of 65 °C. In view of the sensitivity of the assay, concentrations as low as 10 pM TL could be detected. Furthermore, the rate of hydrolysis of Dabcyl-FKFLGKE-EDANS was slow or immeasurable with some other unrelated metallo-, serine- and cysteine proteases, suggesting that the peptide has the potential to serve as a selective substrate for TL and TL-like proteases.
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Affiliation(s)
- Danica L Goulet
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
| | - Usama Fraaz
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
| | - Carly J Zulich
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
| | - Tyson J Pilkington
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
| | - Stefan Siemann
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada.
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Decaneto E, Vasilevskaya T, Kutin Y, Ogata H, Grossman M, Sagi I, Havenith M, Lubitz W, Thiel W, Cox N. Solvent water interactions within the active site of the membrane type I matrix metalloproteinase. Phys Chem Chem Phys 2018; 19:30316-30331. [PMID: 28951896 DOI: 10.1039/c7cp05572b] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Matrix metalloproteinases (MMP) are an important family of proteases which catalyze the degradation of extracellular matrix components. While the mechanism of peptide cleavage is well established, the process of enzyme regeneration, which represents the rate limiting step of the catalytic cycle, remains unresolved. This step involves the loss of the newly formed N-terminus (amine) and C-terminus (carboxylate) protein fragments from the site of catalysis coupled with the inclusion of one or more solvent waters. Here we report a novel crystal structure of membrane type I MMP (MT1-MMP or MMP-14), which includes a small peptide bound at the catalytic Zn site via its C-terminus. This structure models the initial product state formed immediately after peptide cleavage but before the final proton transfer to the bound amine; the amine is not present in our system and as such proton transfer cannot occur. Modeling of the protein, including earlier structural data of Bertini and coworkers [I. Bertini, et al., Angew. Chem., Int. Ed., 2006, 45, 7952-7955], suggests that the C-terminus of the peptide is positioned to form an H-bond network to the amine site, which is mediated by a single oxygen of the functionally important Glu240 residue, facilitating efficient proton transfer. Additional quantum chemical calculations complemented with magneto-optical and magnetic resonance spectroscopies clarify the role of two additional, non-catalytic first coordination sphere waters identified in the crystal structure. One of these auxiliary waters acts to stabilize key intermediates of the reaction, while the second is proposed to facilitate C-fragment release, triggered by protonation of the amine. Together these results complete the enzymatic cycle of MMPs and provide new design criteria for inhibitors with improved efficacy.
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Affiliation(s)
- Elena Decaneto
- Max Planck Institute for Chemical Energy Conversion, Stiftstraße. 34-36, D-45470, Mülheim an der Ruhr, Germany.
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Young CJ, Richard K, Beruar A, Lo SY, Siemann S. An investigation of the pH dependence of copper-substituted anthrax lethal factor and its mechanistic implications. J Inorg Biochem 2018; 182:1-8. [PMID: 29407865 DOI: 10.1016/j.jinorgbio.2018.01.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 12/18/2017] [Accepted: 01/22/2018] [Indexed: 10/18/2022]
Abstract
Anthrax lethal factor (LF) is a zinc-dependent endopeptidase involved in the cleavage of proteins critical to the maintenance of host signaling pathways during anthrax infections. Although zinc is typically regarded as the native metal ion in vivo, LF is highly tolerant to metal substitution, with its replacement by copper yielding an enzyme (CuLF) 4.5-fold more active than the native zinc protein (at pH 7). The current study demonstrates that by careful choice of the buffer, ionic strength, pH and substrate, the activity ratio of CuLF and native LF can be increased to >40-fold. Using a fluorogenic LF substrate, such optimized assay conditions can be exploited to detect LF concentrations as low as 2 pM. In contrast to the zinc form, CuLF was found to be inhibited by bromide and iodide ions, to be resistant to metal loss under acidic conditions, and to display a sharp pH dependence with significantly shifted alkaline limb towards more acidic conditions. The alkaline limb in the enzyme's pH profile is suggested to originate from changes in the protonation state of the metal-bound water molecule which serves as the nucleophile in the catalytic mechanism. Based on these observations and studies on other zinc proteases, a minimal mechanism for LF is proposed.
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Affiliation(s)
- Calvin J Young
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
| | - Kaitlin Richard
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
| | - Ananya Beruar
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
| | - Suet Y Lo
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
| | - Stefan Siemann
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada.
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Meng F, Yang H, Aitha M, George S, Tierney DL, Crowder MW. Biochemical and spectroscopic characterization of the catalytic domain of MMP16 (cdMMP16). J Biol Inorg Chem 2016; 21:523-35. [PMID: 27229514 DOI: 10.1007/s00775-016-1362-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 05/07/2016] [Indexed: 11/25/2022]
Abstract
Membrane-bound matrix metalloproteinase 16 (MMP16/MT3-MMP) is considered a drug target due to its role(s) in disease processes such as cancer and inflammation. Biochemical characterization of MMP16 is critical for developing new generation MMP inhibitors (MMPi), which exhibit high efficacies and selectivities. Herein, a modified over-expression and purification protocol was used to prepare the catalytic domain of MMP16 (cdMMP16). The resulting recombinant enzyme exhibited steady-state kinetic constants of K m = 10.6 ± 0.7 μM and k cat = 1.14 ± 0.02 s(-1), when using FS-6 as substrate, and the enzyme bound 1.8 ± 0.1 eq of Zn(II). The enzymatic activity of cdMMP16 is salt concentration-dependent, and cdMMP16 exhibits autoproteolytic activity under certain conditions, which may be related to an in vivo regulatory mechanism of MMP16 and of other membrane-type MMPs (MT-MMPs). Co(II)-substituted analogs (Co2- and ZnCo) of cdMMP16 were prepared and characterized using several spectroscopic techniques, such as UV-Vis, (1)H NMR, and EXAFS spectroscopies. A well-characterized cdMMP16 is now available for future inhibitor screening efforts.
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Affiliation(s)
- Fan Meng
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH, 45056, USA
| | - Hao Yang
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH, 45056, USA
| | - Mahesh Aitha
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH, 45056, USA
| | - Sam George
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH, 45056, USA
| | - David L Tierney
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH, 45056, USA.
| | - Michael W Crowder
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH, 45056, USA.
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Young CJ, Siemann S. Highly dynamic metal exchange in anthrax lethal factor involves the occupation of an inhibitory metal binding site. Chem Commun (Camb) 2016; 52:11748-51. [DOI: 10.1039/c6cc05460a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Rapid metal exchange in anthrax lethal factor and potentially other zinc enzymes proceeds via the formation of transient bimetallic species.
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Affiliation(s)
- Calvin J. Young
- Department of Chemistry and Biochemistry
- Laurentian University
- Sudbury
- Canada
| | - Stefan Siemann
- Department of Chemistry and Biochemistry
- Laurentian University
- Sudbury
- Canada
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8
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Yang H, Makaroff K, Paz N, Aitha M, Crowder MW, Tierney DL. Metal Ion Dependence of the Matrix Metalloproteinase-1 Mechanism. Biochemistry 2015; 54:3631-9. [PMID: 26018933 DOI: 10.1021/acs.biochem.5b00379] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Matrix metalloproteinase-1 (MMP-1) plays crucial roles in disease-related physiologies and pathological processes in the human body. We report here solution studies of MMP-1, including characterization of a series of mutants designed to bind metal in either the catalytic site or the structural site (but not both). Circular dichroism and fluorescence spectroscopy of the mutants demonstrate the importance of the structural Zn(II) in maintaining both secondary and tertiary structure, while UV-visible, nuclear magnetic resonance, electron paramagnetic resonance, and extended X-ray absorption fine structure show its presence influences the catalytic metal ion's coordination number. The mutants allow us to demonstrate convincingly the preparation of a mixed-metal analogue, Co(C)Zn(S)-MMP-1, with Zn(II) in the structural site and Co(II) in the catalytic site. Stopped-flow fluorescence of the native form, Zn(C)Zn(S)-MMP-1, and the mixed-metal Co(C)Zn(S)-MMP-1 analogue shows that the internal fluorescence of a nearby Trp residue is modulated with catalysis and can be used to monitor reactivity under a number of conditions, opening the door to substrate profiling.
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Affiliation(s)
- Hao Yang
- Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio 45056, United States
| | - Katherine Makaroff
- Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio 45056, United States
| | - Nicholas Paz
- Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio 45056, United States
| | - Mahesh Aitha
- Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio 45056, United States
| | - Michael W Crowder
- Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio 45056, United States
| | - David L Tierney
- Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio 45056, United States
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Lo SY, Säbel CE, Mapletoft JP, Siemann S. Influence of chemical denaturants on the activity, fold and zinc status of anthrax lethal factor. Biochem Biophys Rep 2015; 1:68-77. [PMID: 29124135 PMCID: PMC5668564 DOI: 10.1016/j.bbrep.2015.03.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 03/11/2015] [Accepted: 03/12/2015] [Indexed: 11/17/2022] Open
Abstract
Anthrax lethal factor (LF) is a zinc-dependent endopeptidase which, through a process facilitated by protective antigen, translocates to the host cell cytosol in a partially unfolded state. In the current report, the influence of urea and guanidine hydrochloride (GdnHCl) on LF׳s catalytic function, fold and metal binding was assessed at neutral pH. Both urea and GdnHCl were found to inhibit LF prior to the onset of unfolding, with the inhibition by the latter denaturant being a consequence of its ionic strength. With the exception of demetallated LF (apoLF) in urea, unfolding, as monitored by tryptophan fluorescence spectroscopy, was found to follow a two-state (native to unfolded) mechanism. Analysis of the metal status of LF with 4-(2-pyridylazoresorcinol) (PAR) following urea or GdnHCl exposure suggests the enzyme to be capable of maintaining its metal ion passed the observed unfolding transition in a chelator-inaccessible form. Although an increase in the concentration of the denaturants eventually allowed the chelator access to the protein׳s zinc ion, such process is not correlated with the release of the metal ion. Indeed, significant dissociation of the zinc ion from LF was not observed even at 6 M urea, and only high concentrations of GdnHCl (>3 M) were capable of inducing the release of the metal ion from the protein. Hence, the current study demonstrates not only the propensity of LF to tightly bind its zinc ion beyond the spectroscopically determined unfolding transition, but also the utility of PAR as a structural probe. Lethal factor (LF) is strongly inhibited by guanidine hydrochloride. Except of apoLF in urea, unfolding follows a two-state mechanism. LF shields and retains its zinc ion in an unfolded state. Pyridylazoresorcinol is a useful probe to assess metal accessibility and release.
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Key Words
- 4-(2-pyridylazo)resorcinol
- CD, circular dichroism
- Chemical denaturants
- DPA, dipicolinic acid
- EDTA, ethylenediaminetetraacetic acid
- EF, edema factor
- LF, anthrax lethal factor
- Lethal factor
- MWCO, molecular weight cut-off
- PA, protective antigen
- PAR, 4-(2-pyridylazo)resorcinol
- Protein folding
- S-pNA, lethal factor substrate
- SASA, solvent-accessible surface area
- SOD, superoxide dismutase
- Tryptophan fluorescence
- Zinc
- ZnLF, zinc-containing lethal factor
- cps, counts per second
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Affiliation(s)
- Suet Y. Lo
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
| | - Crystal E. Säbel
- Bharti School of Engineering, Laurentian University, Sudbury, Ontario, Canada
| | | | - Stefan Siemann
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
- Correspondence to: Department of Chemistry and Biochemistry, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario, Canada P3E 2C6. Tel.: +1 705 675 1151; fax: +1 705 675 4844.
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Lo SY, Säbel CE, Webb MI, Walsby CJ, Siemann S. High metal substitution tolerance of anthrax lethal factor and characterization of its active copper-substituted analogue. J Inorg Biochem 2014; 140:12-22. [DOI: 10.1016/j.jinorgbio.2014.06.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 05/27/2014] [Accepted: 06/16/2014] [Indexed: 01/19/2023]
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Nishiyama Y, Taguchi H, Hara M, Planque SA, Mitsuda Y, Paul S. Metal-dependent amyloid β-degrading catalytic antibody construct. J Biotechnol 2014; 180:17-22. [PMID: 24698848 DOI: 10.1016/j.jbiotec.2014.03.026] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 03/05/2014] [Accepted: 03/21/2014] [Indexed: 01/29/2023]
Abstract
Catalytic antibodies (catabodies) that degrade target antigens rapidly are rare. We describe the metal-dependence of catabody construct 2E6, an engineered heterodimer of immunoglobulin light chain variable domains that hydrolyzes amyloid β peptides (Aβ) specifically. In addition to the electrophilic phosphonate inhibitor of serine proteases, the metal chelators ethylenediaminetetraacetic acid (EDTA) and 1,10-phenanthroline completely inhibited the hydrolysis of Aβ by catabody 2E6. Formation of catabody-electrophilic phosphonate inhibitor adducts was unaffected by EDTA, suggesting that the metal exerts a favorable effect on a catalytic step after the initial catabody nucleophilic attack on Aβ. The EDTA inactivated catabody failed to disaggregate fibrillar Aβ, indicating the functional importance of the Aβ hydrolytic activity. Treating the EDTA-inactivated catabody with Zn(2+) or Co(2+) restored the Aβ hydrolytic activity, and Zn(2+)-induced catabody conformational transitions were evident by fluorescence emission spectroscopy. The studies reveal the absolute catabody dependence on a metal cofactor.
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Affiliation(s)
- Yasuhiro Nishiyama
- Chemical Immunology Research Center, Department of Pathology and Laboratory Medicine, University of Texas-Houston Medical School, Houston, TX 77030, USA
| | - Hiroaki Taguchi
- Chemical Immunology Research Center, Department of Pathology and Laboratory Medicine, University of Texas-Houston Medical School, Houston, TX 77030, USA
| | - Mariko Hara
- Chemical Immunology Research Center, Department of Pathology and Laboratory Medicine, University of Texas-Houston Medical School, Houston, TX 77030, USA
| | - Stephanie A Planque
- Chemical Immunology Research Center, Department of Pathology and Laboratory Medicine, University of Texas-Houston Medical School, Houston, TX 77030, USA
| | - Yukie Mitsuda
- Chemical Immunology Research Center, Department of Pathology and Laboratory Medicine, University of Texas-Houston Medical School, Houston, TX 77030, USA
| | - Sudhir Paul
- Chemical Immunology Research Center, Department of Pathology and Laboratory Medicine, University of Texas-Houston Medical School, Houston, TX 77030, USA.
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Montpellier LH, Siemann S. Effect of pH on the catalytic function and zinc content of native and immobilized anthrax lethal factor. FEBS Lett 2013; 587:317-21. [DOI: 10.1016/j.febslet.2012.11.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2012] [Revised: 11/22/2012] [Accepted: 11/30/2012] [Indexed: 10/27/2022]
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