1
|
Abedi E, Kaveh S, Mohammad Bagher Hashemi S. Structure-based modification of a-amylase by conventional and emerging technologies: Comparative study on the secondary structure, activity, thermal stability and amylolysis efficiency. Food Chem 2024; 437:137903. [PMID: 37931423 DOI: 10.1016/j.foodchem.2023.137903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 10/22/2023] [Accepted: 10/27/2023] [Indexed: 11/08/2023]
Abstract
α-Amylase is an endo-enzyme that catalyzes the hydrolysis of starch into shorter oligosaccharides. α-Amylase plays a crucial role in various industries. Manipulated α-amylases are of particular interest due to their remarkable amylolysis efficiency and thermostability for large-scale biotechnological processes. The retained catalytic activity of enzymes is decreased according to extreme pH, temperature, pressure, and chemical reagents. Broad industrial applications of α-amylases need special properties such as stability against temperature, pH, and chelators, and also attain reusability, desirable enzymatic activity, efficiency, and selectivity. Considering the biotechnological importance of α-amylase, its high stability is the most critical challenge for its economic viability. Therefore, improving its functionality and stability recently gained much interest. To achieve this purpose, various emerging technologies in combination with conventional methods on α-Amylases with different sources have been conducted. The present review is an attempt to summarize the effect of various conventional methods and emerging technologies employed to date on α-amylase secondary structure, thermal stability, and performance.
Collapse
Affiliation(s)
- Elahe Abedi
- Department of Food Science and Technology, Faculty of Agriculture, Fasa University, Fasa, Iran
| | - Shima Kaveh
- Department of Food Science and Technology, Faculty of Agriculture, Fasa University, Fasa, Iran.
| | | |
Collapse
|
2
|
Cuéllar-Cruz M, Islas SR, Ramírez-Ramírez N, Pedraza-Reyes M, Moreno A. Protection of the DNA from Selected Species of Five Kingdoms in Nature by Ba(II), Sr(II), and Ca(II) Silica-Carbonates: Implications about Biogenicity and Evolving from Prebiotic Chemistry to Biological Chemistry. ACS OMEGA 2022; 7:37410-37426. [PMID: 36312347 PMCID: PMC9609056 DOI: 10.1021/acsomega.2c04170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 10/05/2022] [Indexed: 06/16/2023]
Abstract
The origin of life on Earth is associated with the Precambrian era, in which the existence of a large diversity of microbial fossils has been demonstrated. Notwithstanding, despite existing evidence of the emergence of life many unsolved questions remain. The first question could be as follows: Which was the inorganic structure that allowed isolation and conservation of the first biomolecules in the existing reduced conditions of the primigenial era? Minerals have been postulated as the ones in charge of protecting theses biomolecules against the external environment. There are calcium, barium, or strontium silica-carbonates, called biomorphs, which we propose as being one of the first inorganic structures in which biomolecules were protected from the external medium. Biomorphs are structures with different biological morphologies that are not formed by cells, but by nanocrystals; some of their morphologies resemble the microfossils found in Precambrian cherts. Even though biomorphs are unknown structures in the geological registry, their similarity with some biological forms, including some Apex fossils, could suggest them as the first "inorganic scaffold" where the first biomolecules became concentrated, conserved, aligned, and duplicated to give rise to the pioneering cell. However, it has not been documented whether biomorphs could have been the primary structures that conserved biomolecules in the Precambrian era. To attain a better understanding on whether biomorphs could have been the inorganic scaffold that existed in the primigenial Earth, the aim of this contribution is to synthesize calcium, barium, and strontium biomorphs in the presence of genomic DNA from organisms of the five kingdoms in conditions emulating the atmosphere of the Precambrian era and that CO2 concentration in conditions emulating current atmospheric conditions. Our results showed, for the first time, the formation of the kerogen signal, which is a marker of biogenicity in fossils, in the biomorphs grown in the presence of DNA. We also found the DNA to be internalized into the structure of biomorphs.
Collapse
Affiliation(s)
- Mayra Cuéllar-Cruz
- Departamento
de Biología, División de Ciencias Naturales y Exactas,
Campus Guanajuato, Universidad de Guanajuato, Noria Alta S/N, Col. Noria Alta,
C.P. 36050, Guanajuato, Mexico
| | - Selene R. Islas
- Instituto
de Ciencias Aplicadas y Tecnología, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, México City, 04510 Mexico
| | - Norma Ramírez-Ramírez
- Departamento
de Biología, División de Ciencias Naturales y Exactas,
Campus Guanajuato, Universidad de Guanajuato, Noria Alta S/N, Col. Noria Alta,
C.P. 36050, Guanajuato, Mexico
| | - Mario Pedraza-Reyes
- Departamento
de Biología, División de Ciencias Naturales y Exactas,
Campus Guanajuato, Universidad de Guanajuato, Noria Alta S/N, Col. Noria Alta,
C.P. 36050, Guanajuato, Mexico
| | - Abel Moreno
- Instituto
de Química, Universidad Nacional
Autónoma de México, Av. Universidad 3000, Ciudad Universitaria, México City 04510. Mexico
| |
Collapse
|
3
|
Li Y, Wu X, Jiang X, Liu L, Wang H. Algicidal activity of Aspergillus niger induced by calcium ion as signal molecule on Microcystis aeruginosa. ALGAL RES 2021. [DOI: 10.1016/j.algal.2021.102536] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
4
|
Shin I, Davis I, Nieves-Merced K, Wang Y, McHardy S, Liu A. A novel catalytic heme cofactor in SfmD with a single thioether bond and a bis-His ligand set revealed by a de novo crystal structural and spectroscopic study. Chem Sci 2021; 12:3984-3998. [PMID: 34163669 PMCID: PMC8179489 DOI: 10.1039/d0sc06369j] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 01/21/2021] [Indexed: 12/13/2022] Open
Abstract
SfmD is a heme-dependent enzyme in the biosynthetic pathway of saframycin A. Here, we present a 1.78 Å resolution de novo crystal structure of SfmD, which unveils a novel heme cofactor attached to the protein with an unusual Hx n HxxxC motif (n ∼ 38). This heme cofactor is unique in two respects. It contains a single thioether bond in a cysteine-vinyl link with Cys317, and the ferric heme has two axial protein ligands, i.e., His274 and His313. We demonstrated that SfmD heme is catalytically active and can utilize dioxygen and ascorbate for a single-oxygen insertion into 3-methyl-l-tyrosine. Catalytic assays using ascorbate derivatives revealed the functional groups of ascorbate essential to its function as a cosubstrate. Abolishing the thioether linkage through mutation of Cys317 resulted in catalytically inactive SfmD variants. EPR and optical data revealed that the heme center undergoes a substantial conformational change with one axial histidine ligand dissociating from the iron ion in response to substrate 3-methyl-l-tyrosine binding or chemical reduction by a reducing agent, such as the cosubstrate ascorbate. The labile axial ligand was identified as His274 through redox-linked structural determinations. Together, identifying an unusual heme cofactor with a previously unknown heme-binding motif for a monooxygenase activity and the structural similarity of SfmD to the members of the heme-based tryptophan dioxygenase superfamily will broaden understanding of heme chemistry.
Collapse
Affiliation(s)
- Inchul Shin
- Department of Chemistry, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
| | - Ian Davis
- Department of Chemistry, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
| | - Karinel Nieves-Merced
- Department of Chemistry, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
- Center for Innovative Drug Discovery, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
| | - Yifan Wang
- Department of Chemistry, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
| | - Stanton McHardy
- Department of Chemistry, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
- Center for Innovative Drug Discovery, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
| | - Aimin Liu
- Department of Chemistry, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
| |
Collapse
|
5
|
Traore ES, Li J, Chiura T, Geng J, Sachla AJ, Yoshimoto F, Eichenbaum Z, Davis I, Mak PJ, Liu A. Heme Binding to HupZ with a C-Terminal Tag from Group A Streptococcus. Molecules 2021; 26:549. [PMID: 33494451 PMCID: PMC7865249 DOI: 10.3390/molecules26030549] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/14/2021] [Accepted: 01/16/2021] [Indexed: 12/23/2022] Open
Abstract
HupZ is an expected heme degrading enzyme in the heme acquisition and utilization pathway in Group A Streptococcus. The isolated HupZ protein containing a C-terminal V5-His6 tag exhibits a weak heme degradation activity. Here, we revisited and characterized the HupZ-V5-His6 protein via biochemical, mutagenesis, protein quaternary structure, UV-vis, EPR, and resonance Raman spectroscopies. The results show that the ferric heme-protein complex did not display an expected ferric EPR signal and that heme binding to HupZ triggered the formation of higher oligomeric states. We found that heme binding to HupZ was an O2-dependent process. The single histidine residue in the HupZ sequence, His111, did not bind to the ferric heme, nor was it involved with the weak heme-degradation activity. Our results do not favor the heme oxygenase assignment because of the slow binding of heme and the newly discovered association of the weak heme degradation activity with the His6-tag. Altogether, the data suggest that the protein binds heme by its His6-tag, resulting in a heme-induced higher-order oligomeric structure and heme stacking. This work emphasizes the importance of considering exogenous tags when interpreting experimental observations during the study of heme utilization proteins.
Collapse
Affiliation(s)
- Ephrahime S. Traore
- Department of Chemistry, The University of Texas at San Antonio, San Antonio, TX 78249, USA; (E.S.T.); (J.L.); (F.Y.); (I.D.)
| | - Jiasong Li
- Department of Chemistry, The University of Texas at San Antonio, San Antonio, TX 78249, USA; (E.S.T.); (J.L.); (F.Y.); (I.D.)
| | - Tapiwa Chiura
- Department of Chemistry, Saint Louis University, St. Louis, MO 63103, USA;
| | - Jiafeng Geng
- Department of Chemistry, Georgia State University, Atlanta, GA 30302, USA;
| | - Ankita J. Sachla
- Department of Biology, Georgia State University, Atlanta, GA 30302, USA; (A.J.S.); (Z.E.)
| | - Francis Yoshimoto
- Department of Chemistry, The University of Texas at San Antonio, San Antonio, TX 78249, USA; (E.S.T.); (J.L.); (F.Y.); (I.D.)
| | - Zehava Eichenbaum
- Department of Biology, Georgia State University, Atlanta, GA 30302, USA; (A.J.S.); (Z.E.)
| | - Ian Davis
- Department of Chemistry, The University of Texas at San Antonio, San Antonio, TX 78249, USA; (E.S.T.); (J.L.); (F.Y.); (I.D.)
- Department of Chemistry, Georgia State University, Atlanta, GA 30302, USA;
| | - Piotr J. Mak
- Department of Chemistry, Saint Louis University, St. Louis, MO 63103, USA;
| | - Aimin Liu
- Department of Chemistry, The University of Texas at San Antonio, San Antonio, TX 78249, USA; (E.S.T.); (J.L.); (F.Y.); (I.D.)
- Department of Chemistry, Georgia State University, Atlanta, GA 30302, USA;
| |
Collapse
|
6
|
Wang Y, Davis I, Chan Y, Naik SG, Griffith WP, Liu A. Characterization of the nonheme iron center of cysteamine dioxygenase and its interaction with substrates. J Biol Chem 2020; 295:11789-11802. [PMID: 32601061 DOI: 10.1074/jbc.ra120.013915] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 06/25/2020] [Indexed: 12/15/2022] Open
Abstract
Cysteamine dioxygenase (ADO) has been reported to exhibit two distinct biological functions with a nonheme iron center. It catalyzes oxidation of both cysteamine in sulfur metabolism and N-terminal cysteine-containing proteins or peptides, such as regulator of G protein signaling 5 (RGS5). It thereby preserves oxygen homeostasis in a variety of physiological processes. However, little is known about its catalytic center and how it interacts with these two types of primary substrates in addition to O2 Here, using electron paramagnetic resonance (EPR), Mössbauer, and UV-visible spectroscopies, we explored the binding mode of cysteamine and RGS5 to human and mouse ADO proteins in their physiologically relevant ferrous form. This characterization revealed that in the presence of nitric oxide as a spin probe and oxygen surrogate, both the small molecule and the peptide substrates coordinate the iron center with their free thiols in a monodentate binding mode, in sharp contrast to binding behaviors observed in other thiol dioxygenases. We observed a substrate-bound B-type dinitrosyl iron center complex in ADO, suggesting the possibility of dioxygen binding to the iron ion in a side-on mode. Moreover, we observed substrate-mediated reduction of the iron center from ferric to the ferrous oxidation state. Subsequent MS analysis indicated corresponding disulfide formation of the substrates, suggesting that the presence of the substrate could reactivate ADO to defend against oxidative stress. The findings of this work contribute to the understanding of the substrate interaction in ADO and fill a gap in our knowledge of the substrate specificity of thiol dioxygenases.
Collapse
Affiliation(s)
- Yifan Wang
- Department of Chemistry, University of Texas at San Antonio, Texas, USA
| | - Ian Davis
- Department of Chemistry, University of Texas at San Antonio, Texas, USA.,Department of Chemistry, Georgia State University, Atlanta, Georgia, USA
| | - Yan Chan
- Department of Chemistry, Georgia State University, Atlanta, Georgia, USA
| | - Sunil G Naik
- Department of Chemistry, University of Texas at San Antonio, Texas, USA
| | | | - Aimin Liu
- Department of Chemistry, University of Texas at San Antonio, Texas, USA .,Department of Chemistry, Georgia State University, Atlanta, Georgia, USA
| |
Collapse
|
7
|
Jeoung S, Shin S, Choi M. Copper-binding energetics of amicyanin in different folding states. Metallomics 2020; 12:273-279. [PMID: 31830170 DOI: 10.1039/c9mt00261h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Amicyanin is a type I copper protein that mediates electron transfer between methylamine dehydrogenase and cytochrome c-551i for energy production in Paracoccus denitrificans. Although the Met98 axial ligand of amicyanin has been shown to dictate metal selectivity and specificity during protein folding, the mechanism involved in copper-mediated amicyanin folding is unknown. Here, we kinetically and spectroscopically described reaction steps for incorporating copper into fully and less folded apo-amicyanin and established thermodynamic parameters for two amicyanin folding states. The rate constant for the incorporation of copper into fully folded apo-amicyanin at 25 °C was almost 1.5-fold lower than that for the initial phase of copper addition to the less folded apo-amicyanin. However, the rate constant was 10-fold higher than that of the second phase of copper addition to less folded apo-amicyanin at 25 °C. When overall binding energetic parameters (ΔH° and ΔS°) for the incorporation of copper into fully folded apo-amicyanin were measured by the van't Hoff method and isothermal titration calorimetry, the values were more positive than those determined for less folded apo-amicyanin. This indicates that during amicyanin biogenesis, copper rapidly binds to an unfolded apo-amicyanin active site, inducing protein folding and favorably influencing subsequent organization of copper ligands.
Collapse
Affiliation(s)
- Seounghun Jeoung
- Interdisciplinary Program of Bioenergy and Biomaterials Graduate School, College of Engineering, Chonnam National University, Gwangju 61186, Republic of Korea.
| | | | | |
Collapse
|
8
|
Kenney GE, Dassama LMK, Manesis AC, Ross MO, Chen S, Hoffman BM, Rosenzweig AC. MbnH is a diheme MauG-like protein associated with microbial copper homeostasis. J Biol Chem 2019; 294:16141-16151. [PMID: 31511324 PMCID: PMC6827288 DOI: 10.1074/jbc.ra119.010202] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Revised: 09/06/2019] [Indexed: 01/09/2023] Open
Abstract
Methanobactins (Mbns) are ribosomally-produced, post-translationally modified peptidic copper-binding natural products produced under conditions of copper limitation. Genes encoding Mbn biosynthetic and transport proteins have been identified in a wide variety of bacteria, indicating a broader role for Mbns in bacterial metal homeostasis. Many of the genes in the Mbn operons have been assigned functions, but two genes usually present, mbnP and mbnH, encode uncharacterized proteins predicted to reside in the periplasm. MbnH belongs to the bacterial diheme cytochrome c peroxidase (bCcP)/MauG protein family, and MbnP contains no domains of known function. Here, we performed a detailed bioinformatic analysis of both proteins and have biochemically characterized MbnH from Methylosinus (Ms.) trichosporium OB3b. We note that the mbnH and mbnP genes typically co-occur and are located proximal to genes associated with microbial copper homeostasis. Our bioinformatics analysis also revealed that the bCcP/MauG family is significantly more diverse than originally appreciated, and that MbnH is most closely related to the MauG subfamily. A 2.6 Å resolution structure of Ms. trichosporium OB3b MbnH combined with spectroscopic data and peroxidase activity assays provided evidence that MbnH indeed more closely resembles MauG than bCcPs, although its redox properties are significantly different from those of MauG. The overall similarity of MbnH to MauG suggests that MbnH could post-translationally modify a macromolecule, such as internalized CuMbn or its uncharacterized partner protein, MbnP. Our results indicate that MbnH is a MauG-like diheme protein that is likely involved in microbial copper homeostasis and represents a new family within the bCcP/MauG superfamily.
Collapse
Affiliation(s)
- Grace E. Kenney
- Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, Illinois 60208
| | - Laura M. K. Dassama
- Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, Illinois 60208
| | - Anastasia C. Manesis
- Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, Illinois 60208
| | - Matthew O. Ross
- Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, Illinois 60208
| | - Siyu Chen
- Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, Illinois 60208
| | - Brian M. Hoffman
- Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, Illinois 60208
| | - Amy C. Rosenzweig
- Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, Illinois 60208, To whom correspondence should be addressed. Tel.:
847-467-5301; Fax:
847-467-6489; E-mail:
| |
Collapse
|
9
|
Rizzolo K, Cohen SE, Weitz AC, López Muñoz MM, Hendrich MP, Drennan CL, Elliott SJ. A widely distributed diheme enzyme from Burkholderia that displays an atypically stable bis-Fe(IV) state. Nat Commun 2019; 10:1101. [PMID: 30846684 PMCID: PMC6405878 DOI: 10.1038/s41467-019-09020-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Accepted: 02/15/2019] [Indexed: 11/09/2022] Open
Abstract
Bacterial diheme peroxidases represent a diverse enzyme family with functions that range from hydrogen peroxide (H2O2) reduction to post-translational modifications. By implementing a sequence similarity network (SSN) of the bCCP_MauG superfamily, we present the discovery of a unique diheme peroxidase BthA conserved in all Burkholderia. Using a combination of magnetic resonance, near-IR and Mössbauer spectroscopies and electrochemical methods, we report that BthA is capable of generating a bis-Fe(IV) species previously thought to be a unique feature of the diheme enzyme MauG. However, BthA is not MauG-like in that it catalytically converts H2O2 to water, and a 1.54-Å resolution crystal structure reveals striking differences between BthA and other superfamily members, including the essential residues for both bis-Fe(IV) formation and H2O2 turnover. Taken together, we find that BthA represents a previously undiscovered class of diheme enzymes, one that stabilizes a bis-Fe(IV) state and catalyzes H2O2 turnover in a mechanistically distinct manner.
Collapse
Affiliation(s)
- Kimberly Rizzolo
- Boston University, Department of Chemistry, Boston, MA, 02215, USA
| | - Steven E Cohen
- Massachusetts Institute of Technology, Department of Chemistry, Cambridge, MA, 02139, USA
| | - Andrew C Weitz
- Carnegie Mellon University, Department of Chemistry, Pittsburgh, PA, 15213, USA
| | | | - Michael P Hendrich
- Carnegie Mellon University, Department of Chemistry, Pittsburgh, PA, 15213, USA
| | - Catherine L Drennan
- Massachusetts Institute of Technology, Department of Chemistry, Cambridge, MA, 02139, USA
- Massachusetts Institute of Technology, Department of Biology, Cambridge, MA, 02139, USA
- Howard Hughes Medical Institute, Cambridge, MA, 02139, USA
| | - Sean J Elliott
- Boston University, Department of Chemistry, Boston, MA, 02215, USA.
| |
Collapse
|
10
|
Heterolytic OO bond cleavage: Functional role of Glu113 during bis-Fe(IV) formation in MauG. J Inorg Biochem 2016; 167:60-67. [PMID: 27907864 DOI: 10.1016/j.jinorgbio.2016.11.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 09/23/2016] [Accepted: 11/08/2016] [Indexed: 01/16/2023]
Abstract
The diheme enzyme MauG utilizes H2O2 to perform oxidative posttranslational modification on a protein substrate. A bis-Fe(IV) species of MauG was previously identified as a key intermediate in this reaction. Heterolytic cleavage of the OO bond of H2O2 drives the formation of the bis-Fe(IV) intermediate. In this work, we tested a hypothesis that a glutamate residue, Glu113 in the distal pocket of the pentacoordinate heme of MauG, facilitates heterolytic OO bond cleavage, thereby leading to bis-Fe(IV) formation. This hypothesis was proposed based on sequence alignment and structural comparison with other H2O2-utilizing hemoenzymes, especially those from the diheme enzyme superfamily that MauG belongs to. Electron paramagnetic resonance (EPR) characterization of the reaction between MauG and H2O2 revealed that mutation of Glu113 inhibited heterolytic OO bond cleavage, in agreement with our hypothesis. This result was further confirmed by the HPLC study in which an analog of H2O2, cumene hydroperoxide, was used to probe the pattern of OO bond cleavage. Together, our data suggest that Glu113 functions as an acid-base catalyst to assist heterolytic OO bond cleavage during the early stage of the catalytic reaction. This work advances our mechanistic understanding of the H2O2-activation process during bis-Fe(IV) formation in MauG.
Collapse
|
11
|
Pu F, Chen N, Xue S. Calcium intake, calcium homeostasis and health. FOOD SCIENCE AND HUMAN WELLNESS 2016. [DOI: 10.1016/j.fshw.2016.01.001] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
12
|
Geng J, Davis I, Liu A. Probing bis-Fe(IV) MauG: experimental evidence for the long-range charge-resonance model. Angew Chem Int Ed Engl 2015; 54:3692-6. [PMID: 25631460 PMCID: PMC4363735 DOI: 10.1002/anie.201410247] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 12/14/2014] [Indexed: 11/08/2022]
Abstract
The biosynthesis of tryptophan tryptophylquinone, a protein-derived cofactor, involves a long-range reaction mediated by a bis-Fe(IV) intermediate of a diheme enzyme, MauG. Recently, a unique charge-resonance (CR) phenomenon was discovered in this intermediate, and a biological, long-distance CR model was proposed. This model suggests that the chemical nature of the bis-Fe(IV) species is not as simple as it appears; rather, it is composed of a collection of resonance structures in a dynamic equilibrium. Here, we experimentally evaluated the proposed CR model by introducing small molecules to, and measuring the temperature dependence of, bis-Fe(IV) MauG. Spectroscopic evidence was presented to demonstrate that the selected compounds increase the decay rate of the bis-Fe(IV) species by disrupting the equilibrium of the resonance structures that constitutes the proposed CR model. The results support this new CR model and bring a fresh concept to the classical CR theory.
Collapse
Affiliation(s)
- Jiafeng Geng
- Department of Chemistry and Center for Diagnostics & Therapeutics, Georgia State University, Atlanta, Georgia, United States, Homepage: http://Feradical.gsu.edu
| | - Ian Davis
- Department of Chemistry and Center for Diagnostics & Therapeutics, Georgia State University, Atlanta, Georgia, United States, Homepage: http://Feradical.gsu.edu
| | - Aimin Liu
- Department of Chemistry and Center for Diagnostics & Therapeutics, Georgia State University, Atlanta, Georgia, United States, Homepage: http://Feradical.gsu.edu
| |
Collapse
|
13
|
Geng J, Davis I, Liu A. Probing Bis-FeIVMauG: Experimental Evidence for the Long-Range Charge-Resonance Model. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201410247] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
14
|
Shin S, Choi M, Williamson HR, Davidson VL. A simple method to engineer a protein-derived redox cofactor for catalysis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1595-601. [PMID: 24858537 DOI: 10.1016/j.bbabio.2014.05.354] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 05/14/2014] [Accepted: 05/16/2014] [Indexed: 10/25/2022]
Abstract
The 6×-Histidine tag which is commonly used for purification of recombinant proteins was converted to a catalytic redox-active center by incorporation of Co(2+). Two examples of the biological activity of this engineered protein-derived cofactor are presented. After inactivation of the natural diheme cofactor of MauG, it was shown that the Co(2+)-loaded 6×His-tag could substitute for the hemes in the H2O2-driven catalysis of tryptophan tryptophylquinone biosynthesis. To further demonstrate that the Co(2+)-loaded 6×His-tag could mediate long range electron transfer, it was shown that addition of H2O2 to the Co(2+)-loaded 6×His-tagged Cu(1+) amicyanin oxidizes the copper site which is 20Å away. These results provide proof of principle for this simple method by which to introduce a catalytic redox-active site into proteins for potential applications in research and biotechnology.
Collapse
Affiliation(s)
- Sooim Shin
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA
| | - Moonsung Choi
- Seoul National University of Science and Technology, College of Energy and Biotechnology, Department of Optometry, Seoul, 139-743, Republic of Korea
| | - Heather R Williamson
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA
| | - Victor L Davidson
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA.
| |
Collapse
|
15
|
Bis-Fe(IV): nature's sniper for long-range oxidation. J Biol Inorg Chem 2014; 19:1057-67. [PMID: 24722994 DOI: 10.1007/s00775-014-1123-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 03/10/2014] [Indexed: 10/25/2022]
Abstract
Iron-dependent enzymes are prevalent in nature and participate in a wide range of biological redox activities. Frequently, high-valence iron intermediates are involved in the catalytic events of iron-dependent enzymes, especially when the activation of peroxide or molecular oxygen is involved. Building on the fundamental framework of iron-oxygen chemistry, these reactive intermediates constantly attract significant attention from the enzymology community. During the past few decades, tremendous efforts from a number of laboratories have been dedicated to the capture and characterization of these intermediates to improve mechanistic understandings. In 2008, an unprecedented bis-Fe(IV) intermediate was reported in a c-type diheme enzyme, MauG, which is involved in the maturation of a tryptophan tryptophylquinone cofactor of methylamine dehydrogenase. This intermediate, although chemically equivalent to well-characterized high-valence iron intermediates, such as compound I, compound ES, and intermediate Q in methane monooxygenase, as well as the hypothetical Fe(V) species in Rieske non-heme oxygenases, is orders of magnitude more stable than these other high-valence species in the absence of its primary substrate. It has recently been discovered that the bis-Fe(IV) intermediate exhibits a unique near-IR absorption feature which has been attributed to a novel charge-resonance phenomenon. This review compares the properties of MauG with structurally related enzymes, summarizes the current knowledge of this new high-valence iron intermediate, including its chemical origin and structural basis, explores the formation and consequences of charge resonance, and recounts the long-range catalytic mechanism in which bis-Fe(IV) participates. Biological strategies for storing oxidizing equivalents with iron ions are also discussed.
Collapse
|
16
|
Xue S, Qiao J, Jiang J, Hubbard K, White N, Wei L, Li S, Liu ZR, Yang JJ. Design of ProCAs (protein-based Gd(3+) MRI contrast agents) with high dose efficiency and capability for molecular imaging of cancer biomarkers. Med Res Rev 2014; 34:1070-99. [PMID: 24615853 DOI: 10.1002/med.21313] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Magnetic resonance imaging (MRI) is the leading imaging technique for disease diagnostics, providing high resolution, three-dimensional images noninvasively. MRI contrast agents are designed to improve the contrast and sensitivity of MRI. However, current clinically used MRI contrast agents have relaxivities far below the theoretical upper limit, which largely prevent advancing molecular imaging of biomarkers with desired sensitivity and specificity. This review describes current progress in the development of a new class of protein-based MRI contrast agents (ProCAs) with high relaxivity using protein design to optimize the parameters that govern relaxivity. Further, engineering with targeting moiety allows these contrast agents to be applicable for molecular imaging of prostate cancer biomarkers by MRI. The developed protein-based contrast agents also exhibit additional in vitro and in vivo advantages for molecular imaging of disease biomarkers, such as high metal-binding stability and selectivity, reduced toxicity, proper blood circulation time, and higher permeability in tumor tissue in addition to improved relaxivities.
Collapse
Affiliation(s)
- Shenghui Xue
- Departments of Chemistry and Biology, Georgia State University, Atlanta, Georgia; Center for Diagnostics & Therapeutics (CDT), Georgia State University, Atlanta, Georgia; Center for Biotechnology and Drug Design, Georgia State University, Atlanta, Georgia
| | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Shin S, Yukl ET, Sehanobish E, Wilmot CM, Davidson VL. Site-directed mutagenesis of Gln103 reveals the influence of this residue on the redox properties and stability of MauG. Biochemistry 2014; 53:1342-9. [PMID: 24517455 PMCID: PMC3985960 DOI: 10.1021/bi5000349] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
The diheme enzyme MauG catalyzes
a six-electron oxidation that
is required for the posttranslational modification of a precursor
of methylamine dehydrogenase (preMADH) to complete the biosynthesis
of its protein-derived cofactor, tryptophan tryptophylquinone (TTQ).
Crystallographic and computational studies have implicated Gln103
in stabilizing the FeIV=O moiety of the bis-FeIV state by hydrogen bonding. The role of Gln103 was probed
by site-directed mutagenesis. Q103L and Q103E mutations resulted in
no expression and very little expression of the protein, respectively.
Q103A MauG exhibited oxidative damage when isolated. Q103N MauG was
isolated at levels comparable to that of wild-type MauG and exhibited
normal activity in catalyzing the biosynthesis of TTQ from preMADH.
The crystal structure of the Q103N MauG–preMADH complex suggests
that a water may mediate hydrogen bonding between the shorter Asn103
side chain and the FeIV=O moiety. The Q103N mutation
caused the two redox potentials associated with the diferric/diferrous
redox couple to become less negative, although the redox cooperativity
of the hemes of MauG was retained. Upon addition of H2O2, Q103N MauG exhibits changes in the absorbance spectrum in
the Soret and near-IR regions consistent with formation of the bis-FeIV redox state. However, the rate of spontaneous return of
the spectrum in the Soret region was 4.5-fold greater for Q103N MauG
than for wild-type MauG. In contrast, the rate of spontaneous decay
of the absorbance at 950 nm, which is associated with charge-resonance
stabilization of the high-valence state, was similar for wild-type
MauG and Q103N MauG. This suggests that as a consequence of the mutation
a different distribution of resonance structures stabilizes the bis-FeIV state. These results demonstrate that subtle changes in
the structure of the side chain of residue 103 can significantly affect
the overall protein stability of MauG and alter the redox properties
of the hemes.
Collapse
Affiliation(s)
- Sooim Shin
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida , Orlando, Florida 32827, United States
| | | | | | | | | |
Collapse
|
18
|
Shin S, Davidson VL. MauG, a diheme enzyme that catalyzes tryptophan tryptophylquinone biosynthesis by remote catalysis. Arch Biochem Biophys 2014; 544:112-8. [PMID: 24144526 PMCID: PMC3946517 DOI: 10.1016/j.abb.2013.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Revised: 10/03/2013] [Accepted: 10/08/2013] [Indexed: 11/30/2022]
Abstract
MauG contains two c-type hemes with atypical physical and catalytic properties. While most c-type cytochromes function simply as electron transfer mediators, MauG catalyzes the completion of tryptophan tryptophylquinone (TTQ)(1) biosynthesis within a precursor protein of methylamine dehydrogenase. This posttranslational modification is a six-electron oxidation that requires crosslinking of two Trp residues, oxygenation of a Trp residue and oxidation of the resulting quinol to TTQ. These reactions proceed via a bis-Fe(IV) state in which one heme is present as Fe(IV)O and the other is Fe(IV) with axial heme ligands provided by His and Tyr side chains. Catalysis does not involve direct contact between the protein substrate and either heme of MauG. Instead it is accomplished by remote catalysis using a hole hopping mechanism of electron transfer in which Trp residues of MauG are reversibly oxidized. In this process, long range electron transfer is coupled to the radical mediated chemical reactions that are required for TTQ biosynthesis.
Collapse
Affiliation(s)
- Sooim Shin
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA
| | - Victor L Davidson
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA.
| |
Collapse
|
19
|
Mutation of Trp(93) of MauG to tyrosine causes loss of bound Ca(2+) and alters the kinetic mechanism of tryptophan tryptophylquinone cofactor biosynthesis. Biochem J 2013; 456:129-37. [PMID: 24024544 DOI: 10.1042/bj20130981] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The dihaem enzyme MauG catalyses a six-electron oxidation required for post-translational modification of preMADH (precursor of methylamine dehydrogenase) to complete the biosynthesis of its TTQ (tryptophan tryptophylquinone) cofactor. Trp93 of MauG is positioned midway between its two haems, and in close proximity to a Ca2+ that is critical for MauG function. Mutation of Trp93 to tyrosine caused loss of bound Ca2+ and changes in spectral features similar to those observed after removal of Ca2+ from WT (wild-type) MauG. However, whereas Ca2+-depleted WT MauG is inactive, W93Y MauG exhibited TTQ biosynthesis activity. The rate of TTQ biosynthesis from preMADH was much lower than that of WT MauG and exhibited highly unusual kinetic behaviour. The steady-state reaction exhibited a long lag phase, the duration of which was dependent on the concentration of preMADH. The accumulation of reaction intermediates, including a diradical species of preMADH and quinol MADH (methylamine dehydrogenase), was detected during this pre-steady-state phase. In contrast, steady-state oxidation of quinol MADH to TTQ, the final step of TTQ biosynthesis, exhibited no lag phase. A kinetic model is presented to explain the long pre-steady-state phase of the reaction of W93Y MauG, and the role of this conserved tryptophan residue in MauG and related dihaem enzymes is discussed.
Collapse
|
20
|
Davidson VL, Wilmot CM. Posttranslational biosynthesis of the protein-derived cofactor tryptophan tryptophylquinone. Annu Rev Biochem 2013; 82:531-50. [PMID: 23746262 DOI: 10.1146/annurev-biochem-051110-133601] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Methylamine dehydrogenase (MADH) catalyzes the oxidative deamination of methylamine to formaldehyde and ammonia. Tryptophan tryptophylquinone (TTQ) is the protein-derived cofactor of MADH required for this catalytic activity. TTQ is biosynthesized through the posttranslational modification of two tryptophan residues within MADH, during which the indole rings of two tryptophan side chains are cross-linked and two oxygen atoms are inserted into one of the indole rings. MauG is a c-type diheme enzyme that catalyzes the final three reactions in TTQ formation. In total, this is a six-electron oxidation process requiring three cycles of MauG-dependent two-electron oxidation events using either H2O2 or O2. The MauG redox form responsible for the catalytic activity is an unprecedented bis-Fe(IV) species. The amino acids of MADH that are modified are ≈ 40 Å from the site where MauG binds oxygen, and the reaction proceeds by a hole hopping electron transfer mechanism. This review addresses these highly unusual aspects of the long-range catalytic reaction mediated by MauG.
Collapse
Affiliation(s)
- Victor L Davidson
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida 32827, USA.
| | | |
Collapse
|
21
|
Abstract
Methylamine dehydrogenase (MADH) requires the cofactor tryptophan tryptophylquinone (TTQ) for activity. TTQ is a posttranslational modification that results from an 8-electron oxidation of two specific tryptophans in the MADH β-subunit. The final 6-electron oxidation is catalyzed by an unusual c-type di-heme enzyme, MauG. The di-ferric enzyme can react with H(2)O(2), but atypically for c-type hemes the di-ferrous enzyme can react with O(2) as well. In both cases, an unprecedented bis-Fe(IV) redox state is formed, composed of a ferryl heme (Fe(IV)=O) with the second heme as Fe(IV) stabilized by His-Tyr axial ligation. Bis-Fe(IV) MauG acts as a potent 2-electron oxidant. Catalysis is long-range and requires a hole hopping electron transfer mechanism. This review highlights the current knowledge and focus of research into this fascinating system.
Collapse
Affiliation(s)
- Carrie M Wilmot
- Department of Biochemistry, Molecular Biology and Biophysics, Minneapolis, Minnesota 55455, USA.
| | | |
Collapse
|
22
|
Abu Tarboush N, Shin S, Geng J, Liu A, Davidson VL. Effects of the loss of the axial tyrosine ligand of the low-spin heme of MauG on its physical properties and reactivity. FEBS Lett 2012; 586:4339-43. [PMID: 23127557 DOI: 10.1016/j.febslet.2012.10.044] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Revised: 10/19/2012] [Accepted: 10/23/2012] [Indexed: 10/27/2022]
Abstract
MauG catalyzes posttranslational modifications of methylamine dehydrogenase to complete the biosynthesis of its protein-derived tryptophan tryptophylquinone (TTQ) cofactor. MauG possesses a five-coordinate high-spin and a six-coordinate low-spin ferric heme, the latter with His-Tyr ligation. Replacement of this tyrosine with lysine generates a MauG variant with only high-spin ferric heme and altered spectroscopic and redox properties. Y294K MauG cannot stabilize the bis-Fe(IV) redox state required for TTQ biosynthesis but instead forms a compound I-like species on reaction with peroxide. The results clarify the role of Tyr ligation of the five-coordinate heme in determining the physical and redox properties and reactivity of MauG.
Collapse
Affiliation(s)
- Nafez Abu Tarboush
- Biochemistry and Physiology Department, College of Medicine, The University of Jordan, Amman 11942, Jordan
| | | | | | | | | |
Collapse
|
23
|
Geng J, Dornevil K, Liu A. Chemical Rescue of the Distal Histidine Mutants of Tryptophan 2,3-Dioxygenase. J Am Chem Soc 2012; 134:12209-18. [DOI: 10.1021/ja304164b] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Jiafeng Geng
- Department of Chemistry & Center for Diagnostics and Therapeutics, Georgia State University, 161 Jesse Hill Jr. Drive, Atlanta, Georgia 30303, United States
| | - Kednerlin Dornevil
- Department of Chemistry & Center for Diagnostics and Therapeutics, Georgia State University, 161 Jesse Hill Jr. Drive, Atlanta, Georgia 30303, United States
| | - Aimin Liu
- Department of Chemistry & Center for Diagnostics and Therapeutics, Georgia State University, 161 Jesse Hill Jr. Drive, Atlanta, Georgia 30303, United States
| |
Collapse
|