The Role of Redox-Active Amino Acids on Compound I Stability, Substrate Oxidation, and Protein Cross-Linking in Yeast CytochromecPeroxidase†

Biochemistry ◽  
2001 ◽  
Vol 40 (49) ◽  
pp. 14942-14951 ◽  
Author(s):  
Thomas D. Pfister ◽  
Alan J. Gengenbach ◽  
Sung Syn ◽  
Yi Lu
Keyword(s):  
Amino Acids ◽  
Substrate Oxidation ◽  
Cross Linking ◽  
Compound I ◽  
Redox Active ◽  
Protein Cross Linking

Tridegin, a Novel Peptidic Inhibitor of Factor XIIIa from the Leech, Haementeria ghilianii, Enhances Fibrinolysis In Vitro

1997 ◽  
Vol 77 (05) ◽  
pp. 0959-0963 ◽  
Author(s):  
Lisa Seale ◽  
Sarah Finney ◽  
Roy T Sawyer ◽  
Robert B Wallis
Keyword(s):  
Potent Inhibitor ◽  
Platelet Rich Plasma ◽  
Factor Xiiia ◽  
Cross Linking ◽  
Fibrinolytic Enzymes ◽  
Small Polypeptide ◽  
Tissue Plasminogen ◽  
Protein Cross Linking

SummaryTridegin is a potent inhibitor of factor Xllla from the leech, Haementeria ghilianii, which inhibits protein cross-linking. It modifies plasmin-mediated fibrin degradation as shown by the absence of D-dimer and approximately halves the time for fibrinolysis. Plasma clots formed in the presence of Tridegin lyse more rapidly when either streptokinase, tissue plasminogen activator or hementin is added 2 h after clot formation. The effect of Tridegin is markedly increased if clots are formed from platelet-rich plasma. Platelet-rich plasma clots are lysed much more slowly by the fibrinolytic enzymes used and if Tridegin is present, the rate of lysis returns almost to that of platelet- free clots. These studies indicate the important role of platelets in conferring resistance to commonly used fibrinolytic enzymes and suggest that protein cross-linking is an important step in this effect. Moreover they indicate that Tridegin, a small polypeptide, may have potential as an adjunct to thrombolytic therapy.

Direct evidence for the role of Maillard reaction products in protein cross-linking in milk powder during storage

2013 ◽  
Vol 31 (2) ◽  
pp. 83-91 ◽  
Author(s):  
Thao T. Le ◽  
John W. Holland ◽  
Bhesh Bhandari ◽  
Paul F. Alewood ◽  
Hilton C. Deeth
Keyword(s):  
Maillard Reaction ◽  
Direct Evidence ◽  
Milk Powder ◽  
Cross Linking ◽  
Maillard Reaction Products ◽  
Reaction Products ◽  
Protein Cross Linking

Role of transglutaminase and protein cross-linking in the repair of mucosal stress erosions

1992 ◽  
Vol 262 (5) ◽  
pp. G818-G825 ◽  
Author(s):  
J. Y. Wang ◽  
L. R. Johnson
Keyword(s):  
Enzyme Activity ◽  
Oral Administration ◽  
Specific Inhibitor ◽  
Duodenal Mucosa ◽  
Mucosal Healing ◽  
Cross Linking ◽  
Xiphoid Process ◽  
Transglutaminase Activity ◽  
Protein Cross Linking

We have recently demonstrated that polyamines are absolutely required for gastric and duodenal mucosal repair after stress. Polyamines act as substrates for transglutaminase and facilitate protein cross-linking. The current study tests whether transglutaminase and protein cross-linking are involved in the mechanism of mucosal healing. Rats were fasted 22 h, placed in restraint cages, and immersed in water to the xiphoid process for 6 h. Animals were killed immediately or 4, 12, or 24 h after stress. Gastric and duodenal mucosa were examined histologically and grossly, and transglutaminase activity was measured. Transglutaminase activity in gastric and duodenal mucosa was increased significantly from 0 to 8 h, peaking 4 h after the 6-h stress period. By 12 h, enzyme activity in duodenal mucosa had returned to control values while gastric mucosal transglutaminase did not decrease to control values until 24 h. Mucosal recovery from lesions produced by stress was evident 12 h after stress and was almost complete by 24 h. Dansylcadaverine (100 mg/kg, orally), a specific inhibitor of protein cross-linking, not only prevented the increases in transglutaminase but significantly decreased healing in both tissues. Oral administration of the polyamine spermidine (100 mg/kg) immediately after stress totally prevented inhibition of repair caused by blocking ornithine decarboxylase with difluoromethylornithine (DFMO, 500 mg/kg). Administration of dansylcadaverine, together with spermidine, significantly prevented the beneficial effect of spermidine on mucosal healing in the DFMO-treated animals.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals The role of the thiol group in protein modification with methylglyoxal

2009 ◽  
Vol 74 (8-9) ◽  
pp. 867-883 ◽  
Author(s):  
Jelena Acimovic ◽  
Bojana Stanimirovic ◽  
Ljuba Mandic
Keyword(s):  
Protein Modification ◽  
Time Course ◽  
Thiol Group ◽  
Model Systems ◽  
Cross Linking ◽  
Thiol Groups ◽  
Serum Albumins ◽  
Stable Product ◽  
Protein Cross Linking

Methylglyoxal is a highly reactive ?-oxoaldehyde with elevated production in hyperglycemia. It reacts with nucleophilic Lys and Arg side-chains and N-terminal amino groups causing protein modification. In the present study, the importance of the reaction of the Cys thiol group with methylglyoxal in protein modification, the competitiveness of this reaction with those of amino and guanidine groups, the time course of these reactions and their role and contribution to protein cross-linking were investigated. Human and bovine serum albumins were used as model systems. It was found that despite the very low levels of thiol groups on the surface of the examined protein molecules (approx. 80 times lower than those of amino and guanidino groups), a very high percentage of it reacts (25-85 %). The amount of reacted thiol groups and the rate of the reaction, the time for the reaction to reach equilibrium, the formation of a stable product and the contribution of thiol groups to protein cross-linking depend on the methylglyoxal concentration. The product formed in the reaction of thiol and an insufficient quantity of methylglyoxal (compared to the concentrations of the groups accessible for modification) participates to a significant extent (4 %) to protein cross-linking. Metformin applied in equimolar concentration with methylglyoxal prevents its reaction with amino and guanidino groups but, however, not with thiol groups.

Pea Seedling Extracts Catalyze Protein Amine Binding and Protein Cross-Linking. 1. Evidence for the Role of a Diamine Oxidase

1996 ◽  
Vol 44 (11) ◽  
pp. 3717-3722
Author(s):  
Marileusa D. Chiarello ◽  
Colette Larré ◽  
Zenon M. Kedzior ◽  
Jacques Gueguen
Keyword(s):  
Diamine Oxidase ◽  
Cross Linking ◽  
Pea Seedling ◽  
Protein Cross Linking

scholarly journals Abiological Catalysis by Myoglobin Mutant with a Genetically Incorporated Unnatural Amino Acid

2021 ◽  
Author(s):  
Subhash Chand ◽  
Sriparna Ray ◽  
Poonam Yadav ◽  
Susruta Samanta ◽  
Brad S Pierce ◽  
...  
Keyword(s):  
Unnatural Amino Acids ◽  
Oxidation Process ◽  
Reference Electrode ◽  
Unnatural Amino Acid ◽  
Genetically Engineered ◽  
Oxygen Storage ◽  
Compound I ◽  
Redox Active ◽  
Additional Hydrogen

To inculcate biocatalytic activity in the oxygen-storage protein myoglobin (Mb), a genetically engineered myoglobin mutant H64DOPA (DOPA = L-3,4-dihydroxyphenylalanine) has been created.  Incorporation of unnatural amino acids has already demonstrated their ability to accomplish many non-natural functions in proteins efficiently.  Herein, the presence of redox-active DOPA residue in the active site of mutant Mb presumably stabilizes the compound I in the catalytic oxidation process by participating in an additional hydrogen bonding (H-bonding) as compared to the WT Mb.  Specifically, a general acid-base catalytic pathway was achieved due to the availability of the hydroxyl moieties of DOPA.  The reduction potential values of WT (E° = - 260 mV) and mutant Mb (E° = - 300 mV), w.r.t. Ag/AgCl reference electrode, in the presence of hydrogen peroxide, indicated an additional H-bonding in the mutant protein, which is responsible for the peroxidase activity of the mutant Mb.  We observed that in the presence of 5 mM H2O2, H64DOPA Mb oxidizes thioanisole and benzaldehyde with a 10 and 54 folds higher rate, respectively, as opposed to WT Mb.  Based on spectroscopic, kinetic, and electrochemical studies, we deduce that DOPA residue, when present within the distal pocket of mutant Mb, alone serves the role of His/Arg-pair of peroxidases.

Activation of cytochrome c to a peroxidase compound I-type intermediate by H2O2: relevance to redox signalling in apoptosis

2004 ◽  
Vol 71 ◽  
pp. 97-106 ◽  
Author(s):  
Mark Burkitt ◽  
Clare Jones ◽  
Andrew Lawrence ◽  
Peter Wardman
Keyword(s):  
Cytochrome C ◽  
Hydroxyl Radical ◽  
Redox Regulation ◽  
Chemotherapeutic Agents ◽  
Tyrosyl Radical ◽  
Compound I ◽  
Definitive Evidence ◽  
Enhanced Production ◽  
Physico Chemical

The release of cytochrome c from mitochondria during apoptosis results in the enhanced production of superoxide radicals, which are converted to H2O2 by Mn-superoxide dismutase. We have been concerned with the role of cytochrome c/H2O2 in the induction of oxidative stress during apoptosis. Our initial studies showed that cytochrome c is a potent catalyst of 2′,7′-dichlorofluorescin oxidation, thereby explaining the increased rate of production of the fluorophore 2′,7′-dichlorofluorescein in apoptotic cells. Although it has been speculated that the oxidizing species may be a ferryl-haem intermediate, no definitive evidence for the formation of such a species has been reported. Alternatively, it is possible that the hydroxyl radical may be generated, as seen in the reaction of certain iron chelates with H2O2. By examining the effects of radical scavengers on 2′,7′-dichlorofluorescin oxidation by cytochrome c/H2O2, together with complementary EPR studies, we have demonstrated that the hydroxyl radical is not generated. Our findings point, instead, to the formation of a peroxidase compound I species, with one oxidizing equivalent present as an oxo-ferryl haem intermediate and the other as the tyrosyl radical identified by Barr and colleagues [Barr, Gunther, Deterding, Tomer and Mason (1996) J. Biol. Chem. 271, 15498-15503]. Studies with spin traps indicated that the oxo-ferryl haem is the active oxidant. These findings provide a physico-chemical basis for the redox changes that occur during apoptosis. Excessive changes (possibly catalysed by cytochrome c) may have implications for the redox regulation of cell death, including the sensitivity of tumour cells to chemotherapeutic agents.

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