Equilibrium Constants of Exchange Reactions of Cystine with Glutathione and with Thioglycolic Acid Both in the Oxidized and Reduced State

Kolthoff, I. M.; Stricks, W.; Kapoor, Ritu

doi:10.1021/ja01623a012

Cited by 74 publications

(23 citation statements)

References 2 publications

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“…It is well known that mixed disulfides are formed by the reaction of disulfide compounds with low molecular SH compounds such as cysteine (10,11). The inter change reaction between disulfides and the SH groups of proteins were also re ported by Klotz et al (6) and Pihl et al (13).…”

Section: Interaction Of Bids and Proteins 47mentioning

confidence: 95%

Studies on Interaction of Thiamine or Its Related Compounds With Proteins

1963

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Section: Interaction Of Bids and Proteins 47mentioning

confidence: 95%

Studies on Interaction of Thiamine or Its Related Compounds With Proteins

1963

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“…Using the value given for K,, in Table 1 parison, EGSSGIGSH -ECSSCICSH, where CSSC is cystine, is reported to be in the range -0.013 to -0.018 V at pH 6.6-7.0 (21,23,27). The stepwise equilibrium constants for thiolldisulfide exchange indicate that the lower reducing power of PSH as compared to cysteine is due to the much smaller tendency of penicillamine to form its symmetrical disulfide from its unsymmetrical, mixed disulfides.…”

Section: Discussionmentioning

confidence: 99%

“…Thiol/disulfide exchange reactions proceed via the thiolate anion (19)(20)(21)(22)(23)(24)(25)(26)(27). There are two thiolate species possible for PSH: PS-, in which the thiol group is deprotonated and the amino group protonated, and PS2-, in which both groups are deprotonated.…”

Section: Penicillamine-glutathione Disulfide Nuclear Magneticmentioning

confidence: 99%

A nuclear magnetic resonance study of the kinetics and equilibria for the oxidation of penicillamine and N-acetylpenicillamine by glutathione disulfide

Rabenstein¹,

Theriault²

1984

Can. J. Chem.

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. J. Chem. 62, 1672 (1984).The kinetics and equilibria of the oxidation of penicillamine by glutathione disulfide to form, in the first step, penicillamine-glutathione mixed disulfide and glutathione and, in the second step, penicillamine disulfide and glutathione have been studied over the pH range 4-9 by 'H nmr. The reactive species are found to be penicillamine with its amino group protonated and its thiol group deprotonated and glutathione disulfide and penicillamine-glutathione mixed disulfide with their two amino groups protonated. The rate and equilibrium constants for the first step are much larger than those for the second step, indicating a small tendency for penicillamine to form its symmetrical disulfide by thiol/disulfide exchange reactions. This and the smaller reducing power of penicillamine as compared to glutathione are attributed to steric hindrance from the methyl groups adjacent to the sulfur. The kinetics and equilibria of the oxidation of N-acetylpenicillarnine by glutathione disulfide were studied at neutral pH. Conditional equilibrium and rate constants for the oxidation of penicillamine by glutathione disulfide at pH 7.4 are presented and discussed in terms of the metabolism of penicillamine.

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“…Using three different SH compounds, Kolthoff et al [8,9] reported a yield of free energy as the result of an FACTORS AFFECTING GROWTH OF C. FETUS 63 exchange reaction among mixed disulfides and thiol compounds. Their examinations supported the evidence that the coexistence of three groups, -SS-, -SH and -SOOH promoted some oxidative reactions in the metabolic pathway.…”

Section: Discussionmentioning

confidence: 99%

Studies on the Growth Conditions of Campylobacter fetus

Miyamae

1974

Japanese Journal of Microbiology

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The optimal growth pH and conditions necessary to give a full manifestation of the effect of reductants upon the growth of Campylobacter ,fetus were investigated using static cultivation. The multiplication of cells was limited to a narrow range of added reductants.Thioglycollate supplemented without heating produced heavy growth in combinations of 0.05% at pH 6.80 or 0.1% at pH 6.60, and 0.2% at pH 7.00 or 7.20. Although the stimulating effect depended upon the time between the addition of the supplement and inoculation, two prominent peaks in the growth curve always appeared with both alkaline and acidic pH ranges of the medium. Autoclaving the medium with some SH compounds brought about this growth only at around pH 6.50. Consequently there was a uniform decrease in the initial pH. L-Cysteine and ascorbic acid also gave similar effects. Glucose remarkably prevented the growth promotion due to SH compounds.Optimal initial reduction potential for growth in a semisolid medium was considered to be -0.05 to -0.08 volt at an initial pH of 6.60. SH compounds supplemented without heating brought about a marked longevity of the culture in comparison with a culture in an autoclaved medium of the same composition. For the growth of C. fetus in semisolid medium, it was important to avoid decreasing the growth-promoting activity of some of the supplemented SH compounds by not heating but adding the supplement aseptically. Also a rigid regulation of the pH, the concentration of the added reductants, and the time of inoculation into the fresh medium were important.

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Equilibrium Constants of Exchange Reactions of Cystine with Glutathione and with Thioglycolic Acid Both in the Oxidized and Reduced State

Cited by 74 publications

References 2 publications

Studies on Interaction of Thiamine or Its Related Compounds With Proteins

Studies on Interaction of Thiamine or Its Related Compounds With Proteins

A nuclear magnetic resonance study of the kinetics and equilibria for the oxidation of penicillamine and N-acetylpenicillamine by glutathione disulfide

Studies on the Growth Conditions of Campylobacter fetus

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