Spinach leaf glyoxylic acid reductase, an enzyme containing two identical or similar subunits, has been shown to have 12 half-cystine residues. Four of these are necessary for catalytic function and can be titrated as free sulfhydryl groups. One mole of cysteinyl residues per mole of enzyme is essential to catalytic activity when evaluated under conditions favoring optimal activity. All free su...

The influence of alcohols with different alkyl chain length (methanol, ethanol and propanol) on the physicochemical properties (turbidity, surface hydrophobicity, exposed total free sulfhydryl ...

the aim of this study was to investigate the effective concentration of ethanolic extract  of bee pollen on liver, spleen and heart tissues of fish. bee pollen extract in various concentrations (0.5, 2.5, 5, 10, 20 and 30 ppm) was administered to fish for 96 h under aquarium conditions. the malondialdehyde (mda) levels, total antioxidant status (tas), total oxidant status (tos), oxidative stres...

Two groups of male guinea pigs were exposed to 5 and 10 p.p.m. nitrogen dioxide, 2 hr daily for 35 consecutive days, respectively. The third group, exposed to clean room air, was used as control. Total, free and protein bound sulfhydryl groups were estimated in the cerebral hemisphere cerebellum, midbrain and spinal cord. Significant decrement in total and protein bound sulfhydryl groups and in...

Free sulfhydryl and disulfide groups of an acid-soluble and acid-precipitable fraction and of isolated plasma membranes were quantified in fresh and stored human platelets. Fresh platelets contained 26.6 X 10 moles of total thiols including hee sulfhydryl and disulfide groups per iO cells. One-third of these thiols were present as disulfides. Acid-soluble thiols accounted for one-tenth of the t...

Free sulfhydryl and disulfide groups of an acid-soluble and acid-precipitable fraction and of isolated plasma membranes were quantified in fresh and stored human platelets. Fresh platelets contained 26.6 X 10 moles of total thiols including hee sulfhydryl and disulfide groups per iO cells. One-third of these thiols were present as disulfides. Acid-soluble thiols accounted for one-tenth of the t...

Wherever the point has been examined (e.g. References l-6), pyridoxal phosphate enzymes have been found to require free sulfhydryl groups for activity. The functional role played by these groups, however, has not been clear. In glutamate-oxaloacetate transaminase, which has been studied most extensively, no spectrophotometric or enzymatic evidence for their participation in coenzyme binding was...

Acetaminophen (APAP)-induced liver injury is the leading cause of acute liver failure in many countries. This study determined the extent of liver protein sulfhydryl depletion not only in whole liver homogenate but also in the zonal pattern of sulfhydryl depletion within the liver lobule. A single oral gavage dose of 150 or 300 mg/kg APAP in B6C3F1 mice produced increased serum alanine aminotra...

The free sulfhydryls of brain tubulin prepared by cyclic polymerization procedures both with and without glycerol have been examined. The average free sulfhydryl titer of tubulin prepared with glycerol (7.0 sulfhydryls/55,000 mol wt) is greater than that of tubulin prepared without glycerol (4.0 sulfhydryls/55,000 mol wt). Diamide, a sulfhydryl-oxidizing agent, inhibits the polymerization of tu...

Several lines of investigation were pursued to understand mechanisms involved in the in vivo depression of rat hepatic microsomal mixed function oxidase by cyclophosphamide, an important anti-cancer and immunosuppressive agent. Essentially exclusive metabolism-dependent binding to microsomal proteins of 14C from [4-14C]cyclophosphamide, compared with 3H from [chloroethyl-3H]cyclophosphamide, su...