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  1. Article: Sequestration of carbon dioxide by the hydrophobic pocket of the carbonic anhydrases.

    Domsic, John F / McKenna, Robert

    Biochimica et biophysica acta

    2009  Volume 1804, Issue 2, Page(s) 326–331

    Abstract: The interaction between carbon dioxide (CO(2)) and the alpha-class carbonic anhydrase, human CA 2 (HCA2) exists for only a short period due to the rapid catalytic turnover by this enzyme. The fleeting nature of this interaction has led to difficulties in ...

    Abstract The interaction between carbon dioxide (CO(2)) and the alpha-class carbonic anhydrase, human CA 2 (HCA2) exists for only a short period due to the rapid catalytic turnover by this enzyme. The fleeting nature of this interaction has led to difficulties in its direct analysis, with previous studies placing the CO(2) in the hydrophobic pocket of HCA2's active site. A more precise location was determined via the crystal structure of CO(2) trapped in both wild-type (holo) and zinc-free (apo) HCA2. This provided a detailed description of the means by which CO(2) is held and orientated for optimal catalysis. This information can be extended to the beta and gamma class enzymes to help elucidate the binding mode of CO(2) in these enzymes.
    MeSH term(s) Animals ; Carbon Dioxide/chemistry ; Carbon Dioxide/metabolism ; Carbonic Anhydrases/chemistry ; Carbonic Anhydrases/metabolism ; Catalysis ; Humans ; Hydrophobic and Hydrophilic Interactions
    Chemical Substances Carbon Dioxide (142M471B3J) ; Carbonic Anhydrases (EC 4.2.1.1)
    Language English
    Publishing date 2009-08-11
    Publishing country Netherlands
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Review
    ZDB-ID 60-7
    ISSN 1879-2596 ; 1879-260X ; 1872-8006 ; 1879-2642 ; 1879-2618 ; 1879-2650 ; 0006-3002 ; 0005-2728 ; 0005-2736 ; 0304-4165 ; 0167-4838 ; 1388-1981 ; 0167-4889 ; 0167-4781 ; 0304-419X ; 1570-9639 ; 0925-4439 ; 1874-9399
    ISSN (online) 1879-2596 ; 1879-260X ; 1872-8006 ; 1879-2642 ; 1879-2618 ; 1879-2650
    ISSN 0006-3002 ; 0005-2728 ; 0005-2736 ; 0304-4165 ; 0167-4838 ; 1388-1981 ; 0167-4889 ; 0167-4781 ; 0304-419X ; 1570-9639 ; 0925-4439 ; 1874-9399
    DOI 10.1016/j.bbapap.2009.07.025
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Molecular basis for oligomeric-DNA binding and episome maintenance by KSHV LANA.

    Domsic, John F / Chen, Horng-Shen / Lu, Fang / Marmorstein, Ronen / Lieberman, Paul M

    PLoS pathogens

    2013  Volume 9, Issue 10, Page(s) e1003672

    Abstract: LANA is the KSHV-encoded terminal repeat binding protein essential for viral replication and episome maintenance during latency. We have determined the X-ray crystal structure of LANA C-terminal DNA binding domain (LANADBD) to reveal its capacity to form ...

    Abstract LANA is the KSHV-encoded terminal repeat binding protein essential for viral replication and episome maintenance during latency. We have determined the X-ray crystal structure of LANA C-terminal DNA binding domain (LANADBD) to reveal its capacity to form a decameric ring with an exterior DNA binding surface. The dimeric core is structurally similar to EBV EBNA1 with an N-terminal arm that regulates DNA binding and is required for replication function. The oligomeric interface between LANA dimers is dispensable for single site DNA binding, but is required for cooperative DNA binding, replication function, and episome maintenance. We also identify a basic patch opposite of the DNA binding surface that is responsible for the interaction with BRD proteins and contributes to episome maintenance function. The structural features of LANADBD suggest a novel mechanism of episome maintenance through DNA-binding induced oligomeric assembly.
    MeSH term(s) Antigens, Viral/chemistry ; Antigens, Viral/genetics ; Antigens, Viral/metabolism ; Cell Line, Tumor ; DNA Replication ; DNA, Viral/chemistry ; DNA, Viral/genetics ; DNA, Viral/metabolism ; Herpesvirus 8, Human/chemistry ; Herpesvirus 8, Human/genetics ; Herpesvirus 8, Human/metabolism ; Humans ; Nuclear Proteins/chemistry ; Nuclear Proteins/genetics ; Nuclear Proteins/metabolism ; Plasmids/chemistry ; Plasmids/genetics ; Plasmids/metabolism ; Protein Binding ; Protein Multimerization ; Protein Structure, Quaternary ; Protein Structure, Tertiary ; Structure-Activity Relationship
    Chemical Substances Antigens, Viral ; DNA, Viral ; Nuclear Proteins ; latency-associated nuclear antigen
    Language English
    Publishing date 2013-10-17
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 2205412-1
    ISSN 1553-7374 ; 1553-7366
    ISSN (online) 1553-7374
    ISSN 1553-7366
    DOI 10.1371/journal.ppat.1003672
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  3. Article ; Online: Systemic sclerosis associated interstitial lung disease: a conceptual framework for subclinical, clinical and progressive disease.

    Roofeh, David / Brown, Kevin K / Kazerooni, Ella A / Tashkin, Donald / Assassi, Shervin / Martinez, Fernando / Wells, Athol U / Raghu, Ganesh / Denton, Christopher P / Chung, Lorinda / Hoffmann-Vold, Anna-Maria / Distler, Oliver / Johannson, Kerri A / Allanore, Yannick / Matteson, Eric L / Kawano-Dourado, Leticia / Pauling, John D / Seibold, James R / Volkmann, Elizabeth R /
    Walsh, Simon L F / Oddis, Chester V / White, Eric S / Barratt, Shaney L / Bernstein, Elana J / Domsic, Robyn T / Dellaripa, Paul F / Conway, Richard / Rosas, Ivan / Bhatt, Nitin / Hsu, Vivien / Ingegnoli, Francesca / Kahaleh, Bashar / Garcha, Puneet / Gupta, Nishant / Khanna, Surabhi / Korsten, Peter / Lin, Celia / Mathai, Stephen C / Strand, Vibeke / Doyle, Tracy J / Steen, Virginia / Zoz, Donald F / Ovalles-Bonilla, Juan / Rodriguez-Pinto, Ignasi / Shenoy, Padmanabha D / Lewandoski, Andrew / Belloli, Elizabeth / Lescoat, Alain / Nagaraja, Vivek / Ye, Wen / Huang, Suiyuan / Maher, Toby / Khanna, Dinesh

    Rheumatology (Oxford, England)

    2022  Volume 62, Issue 5, Page(s) 1877–1886

    Abstract: Objectives: To establish a framework by which experts define disease subsets in systemic sclerosis associated interstitial lung disease (SSc-ILD).: Methods: A conceptual framework for subclinical, clinical and progressive ILD was provided to 83 ... ...

    Abstract Objectives: To establish a framework by which experts define disease subsets in systemic sclerosis associated interstitial lung disease (SSc-ILD).
    Methods: A conceptual framework for subclinical, clinical and progressive ILD was provided to 83 experts, asking them to use the framework and classify actual SSc-ILD patients. Each patient profile was designed to be classified by at least four experts in terms of severity and risk of progression at baseline; progression was based on 1-year follow-up data. A consensus was reached if ≥75% of experts agreed. Experts provided information on which items were important in determining classification.
    Results: Forty-four experts (53%) completed the survey. Consensus was achieved on the dimensions of severity (75%, 60 of 80 profiles), risk of progression (71%, 57 of 80 profiles) and progressive ILD (60%, 24 of 40 profiles). For profiles achieving consensus, most were classified as clinical ILD (92%), low risk (54%) and stable (71%). Severity and disease progression overlapped in terms of framework items that were most influential in classifying patients (forced vital capacity, extent of lung involvement on high resolution chest CT [HRCT]); risk of progression was influenced primarily by disease duration.
    Conclusions: Using our proposed conceptual framework, international experts were able to achieve a consensus on classifying SSc-ILD patients along the dimensions of disease severity, risk of progression and progression over time. Experts rely on similar items when classifying disease severity and progression: a combination of spirometry and gas exchange and quantitative HRCT.
    MeSH term(s) Humans ; Lung Diseases, Interstitial/complications ; Scleroderma, Systemic/complications ; Vital Capacity ; Tomography, X-Ray Computed/methods ; Severity of Illness Index ; Lung
    Language English
    Publishing date 2022-09-29
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 1464822-2
    ISSN 1462-0332 ; 1462-0324
    ISSN (online) 1462-0332
    ISSN 1462-0324
    DOI 10.1093/rheumatology/keac557
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Molecular basis for oligomeric-DNA binding and episome maintenance by KSHV LANA.

    John F Domsic / Horng-Shen Chen / Fang Lu / Ronen Marmorstein / Paul M Lieberman

    PLoS Pathogens, Vol 9, Iss 10, p e

    2013  Volume 1003672

    Abstract: LANA is the KSHV-encoded terminal repeat binding protein essential for viral replication and episome maintenance during latency. We have determined the X-ray crystal structure of LANA C-terminal DNA binding domain (LANADBD) to reveal its capacity to form ...

    Abstract LANA is the KSHV-encoded terminal repeat binding protein essential for viral replication and episome maintenance during latency. We have determined the X-ray crystal structure of LANA C-terminal DNA binding domain (LANADBD) to reveal its capacity to form a decameric ring with an exterior DNA binding surface. The dimeric core is structurally similar to EBV EBNA1 with an N-terminal arm that regulates DNA binding and is required for replication function. The oligomeric interface between LANA dimers is dispensable for single site DNA binding, but is required for cooperative DNA binding, replication function, and episome maintenance. We also identify a basic patch opposite of the DNA binding surface that is responsible for the interaction with BRD proteins and contributes to episome maintenance function. The structural features of LANADBD suggest a novel mechanism of episome maintenance through DNA-binding induced oligomeric assembly.
    Keywords Immunologic diseases. Allergy ; RC581-607 ; Biology (General) ; QH301-705.5
    Subject code 570
    Language English
    Publishing date 2013-01-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article ; Online: Emerging from pseudo-symmetry: the redetermination of human carbonic anhydrase II in monoclinic P2(1) with a doubled a axis.

    Robbins, Arthur H / Domsic, John F / Agbandje-McKenna, Mavis / McKenna, Robert

    Acta crystallographica. Section D, Biological crystallography

    2010  Volume 66, Issue Pt 8, Page(s) 950–952

    Abstract: The crystal structure of human carbonic anhydrase II in the monoclinic P2(1) space group with a doubled a axis from that of the usually observed unit cell has recently been reported, with one of the two molecules in the asymmetric unit demonstrating ... ...

    Abstract The crystal structure of human carbonic anhydrase II in the monoclinic P2(1) space group with a doubled a axis from that of the usually observed unit cell has recently been reported, with one of the two molecules in the asymmetric unit demonstrating rotational disorder [Robbins et al. (2010), Acta Cryst. D66, 628-634]. The structure has been redetermined, with the coordinates of both pseudo-symmetrically related molecules in the crystallographic asymmetric unit translated by x' = x +/- 1/4, and no rotational disorder is observed. This corresponds to a different choice of how the four molecules in the unit cell should be grouped into pairs that represent a single asymmetric unit.
    MeSH term(s) Carbonic Anhydrase II/chemistry ; Crystallography, X-Ray ; Humans
    Chemical Substances Carbonic Anhydrase II (EC 4.2.1.-)
    Language English
    Publishing date 2010-07-09
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 2020492-9
    ISSN 1399-0047 ; 0907-4449
    ISSN (online) 1399-0047
    ISSN 0907-4449
    DOI 10.1107/S0907444910023723
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  6. Article ; Online: Clinical characteristics, visceral involvement, and mortality in at-risk or early diffuse systemic sclerosis: a longitudinal analysis of an observational prospective multicenter US cohort.

    Jaafar, Sara / Lescoat, Alain / Huang, Suiyuan / Gordon, Jessica / Hinchcliff, Monique / Shah, Ami A / Assassi, Shervin / Domsic, Robyn / Bernstein, Elana J / Steen, Virginia / Elliott, Sabrina / Hant, Faye / Castelino, Flavia V / Shanmugam, Victoria K / Correia, Chase / Varga, John / Nagaraja, Vivek / Roofeh, David / Frech, Tracy /
    Khanna, Dinesh

    Arthritis research & therapy

    2021  Volume 23, Issue 1, Page(s) 170

    Abstract: Background: Early diffuse cutaneous systemic sclerosis (dcSSc) has the highest case fatality among rheumatic diseases. We report baseline characteristics, current immunosuppressive therapies, progression of skin and internal organ involvement, and ... ...

    Abstract Background: Early diffuse cutaneous systemic sclerosis (dcSSc) has the highest case fatality among rheumatic diseases. We report baseline characteristics, current immunosuppressive therapies, progression of skin and internal organ involvement, and mortality in a multicenter prospective cohort from the United States (US) of America.
    Methods: We performed a longitudinal analysis of participants from 12 US centers, from April 2012 to July 2020. All participants had early dcSSc or were at-risk for dcSSc, with ≤2 years since the first non-Raynaud's phenomenon (RP) symptom.
    Results: Three hundred one patients were included with a baseline median disease duration of 1.2 years since RP and a mean modified skin score of 21.1 units. At baseline, 263 (87.3%) had definite dcSSc and 38 (12.7%) were classified as at-risk; 112 (49.6%) patients were positive for anti-RNA polymerase III antibodies. The median follow-up duration was 24.5 months (IQR = 10.3-40.7 months). One hundred ninety (63.1%) participants were treated with an immunosuppressive therapy, of which mycophenolate mofetil was most used at baseline and follow-up. Of 38 who were classified as at-risk at baseline, 27 (71%) went on to develop dcSSc; these patients were characterized by higher baseline mean HAQ-DI (0.8 versus 0.4, p = 0.05) and higher baseline mRSS (8.8 versus 4.4, p < 0.01) in comparison with those who remained as limited cutaneous SSc. In the overall cohort, 48 participants (21.1%) had clinically significant worsening of skin fibrosis, mainly occurring in the first year of follow-up; 41 (23.3%) had an absolute forced vital capacity decline of ≥10%. Twenty participants (6.6%) died, of which 18 died in the first 3 years of follow-up. Cardiac involvement (33.3%), gastrointestinal dysmotility (22.2%), and progressive interstitial lung disease (ILD) (16.7%) were the main causes of death.
    Conclusion: This US cohort highlights the management of early SSc in the current era, demonstrating progression of skin and lung involvement despite immunosuppressive therapy and high mortality due to cardiac involvement.
    MeSH term(s) Cohort Studies ; Humans ; Lung Diseases, Interstitial ; Mycophenolic Acid ; Prospective Studies ; Scleroderma, Diffuse ; Scleroderma, Systemic ; United States
    Chemical Substances Mycophenolic Acid (HU9DX48N0T)
    Language English
    Publishing date 2021-06-14
    Publishing country England
    Document type Journal Article ; Multicenter Study ; Observational Study ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2107602-9
    ISSN 1478-6362 ; 1478-6354
    ISSN (online) 1478-6362
    ISSN 1478-6354
    DOI 10.1186/s13075-021-02548-1
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  7. Article ; Online: Structure of a monoclinic polymorph of human carbonic anhydrase II with a doubled a axis.

    Robbins, Arthur H / Domsic, John F / Agbandje-McKenna, Mavis / McKenna, Robert

    Acta crystallographica. Section D, Biological crystallography

    2010  Volume 66, Issue Pt 5, Page(s) 628–634

    Abstract: The crystal structure of human carbonic anhydrase II with a doubled a axis from that of the usually observed monoclinic unit cell has been determined and refined to 1.4 A resolution. The diffraction data with h = 2n + 1 were systematically weaker than ... ...

    Abstract The crystal structure of human carbonic anhydrase II with a doubled a axis from that of the usually observed monoclinic unit cell has been determined and refined to 1.4 A resolution. The diffraction data with h = 2n + 1 were systematically weaker than those with h = 2n. Consequently, the scaling of the data, structure solution and refinement were challenging. The two molecules comprising the asymmetric unit are related by a noncrystallographic translation of (1/2) along a, but one of the molecules has two alternate positions related by a rotation of approximately 2 degrees. This rotation axis is located near the edge of the central beta-sheet, causing a maximum distance disparity of 1.7 A between equivalent atoms on the diametrically opposite side of the molecule. The crystal-packing contacts are similar to two sequential combined unit cells along a of the previously determined monoclinic unit cell. Abnormally high final R(cryst) and R(free) values (20.2% and 23.7%, respectively) are not unusual for structures containing pseudo-translational symmetry and probably result from poor signal to noise in the weak h-odd data.
    MeSH term(s) Carbonic Anhydrase II/chemistry ; Crystallization ; Crystallography, X-Ray ; Humans ; Models, Molecular ; Protein Conformation
    Chemical Substances Carbonic Anhydrase II (EC 4.2.1.-)
    Language English
    Publishing date 2010-04-21
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 2020492-9
    ISSN 1399-0047 ; 0907-4449
    ISSN (online) 1399-0047
    ISSN 0907-4449
    DOI 10.1107/S0907444910006797
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  8. Article ; Online: Role of Trp19 and Tyr200 in catalysis by the γ-class carbonic anhydrase from Methanosarcina thermophila.

    Zimmerman, Sabrina / Domsic, John F / Tu, Chingkuang / Robbins, Arthur H / McKenna, Robert / Silverman, David N / Ferry, James G

    Archives of biochemistry and biophysics

    2012  Volume 529, Issue 1, Page(s) 11–17

    Abstract: Although widely distributed in Nature, only two γ class carbonic anhydrases are reported besides the founding member (Cam). Although roles for active-site residues important for catalysis have been identified in Cam, second shell residues have not been ... ...

    Abstract Although widely distributed in Nature, only two γ class carbonic anhydrases are reported besides the founding member (Cam). Although roles for active-site residues important for catalysis have been identified in Cam, second shell residues have not been investigated. Two residues (Trp19 and Tyr200), positioned distant from the catalytic metal, were investigated by structural and kinetic analyses of replacement variants. Steady-state k(cat)/K(m) and k(cat) values decreased 3- to 10-fold for the Trp19 variants whereas the Y200 variants showed up to a 5-fold increase in k(cat). Rate constants for proton transfer decreased up to 10-fold for the Trp19 variants, and an increase of ~2-fold for Y200F. The pK(a) values for the proton donor decreased 1-2 pH units for Trp19 and Y200 variants. The variant structures revealed a loop composed of residues 62-64 that occupies a different conformation than previously reported. The results show that, although Trp19 and Y200 are non-essential, they contribute to an extended active-site structure distant from the catalytic metal that fine tunes catalysis. Trp19 is important for both CO(2)/bicarbonate interconversion, and the proton transfer step of catalysis.
    MeSH term(s) Archaeal Proteins/chemistry ; Archaeal Proteins/genetics ; Archaeal Proteins/metabolism ; Carbonic Anhydrases/chemistry ; Carbonic Anhydrases/genetics ; Carbonic Anhydrases/metabolism ; Catalysis ; Catalytic Domain ; Crystallography, X-Ray ; Escherichia coli/genetics ; Hydrogen-Ion Concentration ; Kinetics ; Methanosarcina/chemistry ; Methanosarcina/enzymology ; Models, Molecular ; Mutation ; Protein Structure, Secondary ; Protons ; Recombinant Proteins/chemistry ; Recombinant Proteins/genetics ; Recombinant Proteins/metabolism ; Tryptophan/chemistry ; Tryptophan/metabolism ; Tyrosine/chemistry ; Tyrosine/metabolism
    Chemical Substances Archaeal Proteins ; Protons ; Recombinant Proteins ; Tyrosine (42HK56048U) ; Tryptophan (8DUH1N11BX) ; Carbonic Anhydrases (EC 4.2.1.1)
    Language English
    Publishing date 2012-10-27
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 523-x
    ISSN 1096-0384 ; 0003-9861
    ISSN (online) 1096-0384
    ISSN 0003-9861
    DOI 10.1016/j.abb.2012.10.010
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  9. Article: Genomic evolution in a virus under specific selection for host recognition.

    Pepin, Kim M / Domsic, John / McKenna, Robert

    Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases

    2008  Volume 8, Issue 6, Page(s) 825–834

    Abstract: ... accessible major capsid protein F appeared to be involved in capsid stability rather than specific ...

    Abstract Genetic variation in viral structural proteins is often explained by evolutionary escape of strong host defenses through processes such as immune evasion, host switching, and tissue tropism. An understanding of the mechanisms driving evolutionary change in virus surface proteins is key to designing effective intervention strategies to disease emergence. This study investigated the predictability of virus genomic evolution in response to highly specific differences in host receptor structure. The bacteriophage PhiX174 was evolved on three E. coli mutant hosts, each differing only by a single sugar group in the lipopolysaccharides, used for phage attachment. Large phage populations were used in order to maximize the amount of sequence space explored by mutation, and thus the potential for parallel evolution. Repeatability was assessed by genome sequencing of multiple isolates from endpoint populations and by fitness of the endpoint population relative to its ancestor. Evolutionary lines showed similar magnitudes of fitness increase between treatments. Only one mutation, occurring in the internal DNA pilot protein H, was completely repeatable, and it appeared to be a necessary stepping stone toward further adaptive change. Substitutions in the surface accessible major capsid protein F appeared to be involved in capsid stability rather than specific interactions with host receptors, suggesting that non-specific alterations to capsid structure could be an important component of adaptation to novel hosts. 33% of mutations were synonymous and showed evidence of selection on codon usage. Lastly, results supported previous findings that evolving populations of small ssDNA viruses may maintain relatively high levels of genetic variation.
    MeSH term(s) Adaptation, Biological ; Bacteriophage phi X 174/genetics ; Bacteriophage phi X 174/growth & development ; DNA Mutational Analysis ; Escherichia coli/virology ; Evolution, Molecular ; Genes, Viral ; Genome, Viral ; Models, Molecular ; Mutation ; Protein Conformation ; Selection, Genetic ; Viral Proteins/chemistry ; Viral Proteins/genetics
    Chemical Substances Viral Proteins
    Language English
    Publishing date 2008-12
    Publishing country Netherlands
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 2037068-4
    ISSN 1567-1348
    ISSN 1567-1348
    DOI 10.1016/j.meegid.2008.08.008
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  10. Article: Role of a glutamate bridge spanning the dimeric interface of human manganese superoxide dismutase.

    Quint, Patrick S / Domsic, John F / Cabelli, Diane E / McKenna, Robert / Silverman, David N

    Biochemistry

    2008  Volume 47, Issue 16, Page(s) 4621–4628

    Abstract: The function in the structure, stability, and catalysis of the interfaces between subunits in manganese superoxide dismutase (MnSOD) is currently under scrutiny. Glu162 in homotetrameric human MnSOD spans a dimeric interface and forms a hydrogen bond ... ...

    Abstract The function in the structure, stability, and catalysis of the interfaces between subunits in manganese superoxide dismutase (MnSOD) is currently under scrutiny. Glu162 in homotetrameric human MnSOD spans a dimeric interface and forms a hydrogen bond with His163 of an adjacent subunit which is a direct ligand of the manganese. We have examined the properties of two site-specific mutants of human MnSOD in which Glu162 is replaced with Asp (E162D) and Ala (E162A). The X-ray crystal structures of E162D and E162A MnSOD reveal no significant structural changes compared with the wild type other than the removal of the hydrogen bond interaction with His163 in E162A MnSOD. In the case of E162D MnSOD, an intervening solvent molecule fills the void created by the mutation to conserve the hydrogen bond interaction between His163 and residue 162. These mutants retain their tetrameric structure and their specificity for manganese over iron. Each has catalytic activity in the disproportionation of superoxide that is typically 5-25% of that of the wild-type enzyme and a level of product inhibition greater by approximately 2-fold. Differential scanning calorimetry indicates that the hydrogen bond between Glu162 and His163 contributes to the stability of MnSOD, with the major unfolding transition occurring at 81 degrees C for E162A compared to 90 degrees C for wild-type MnSOD. These results suggest that Glu162 at the tetrameric interface in human MnSOD supports stability and efficient catalysis and has a significant role in regulating product inhibition.
    MeSH term(s) Catalysis ; Dimerization ; Glutamic Acid/genetics ; Glutamic Acid/metabolism ; Humans ; Hydrogen-Ion Concentration ; Models, Molecular ; Mutation/genetics ; Protein Denaturation ; Protein Structure, Quaternary ; Protein Structure, Tertiary ; Superoxide Dismutase/chemistry ; Superoxide Dismutase/genetics ; Superoxide Dismutase/metabolism ; Temperature ; X-Ray Diffraction
    Chemical Substances Glutamic Acid (3KX376GY7L) ; Superoxide Dismutase (EC 1.15.1.1)
    Language English
    Publishing date 2008-04-22
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 1108-3
    ISSN 1520-4995 ; 0006-2960
    ISSN (online) 1520-4995
    ISSN 0006-2960
    DOI 10.1021/bi7024518
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