Arthur Wainer

The production of cysteinesulfinic acid from cysteine in vitro.

Abstract The synthesis of cysteinesulfinic acid from cysteine by the 105000 × g supernatant of rat liver is described. A method for 5- to 10-fold purification of the activity is presented. Properties of the activity according to cysteine and cysteinesulfinic acid concentrations, pH, time of incubation and use of cystine as a substrate are examined. The variation of cysteinesulfinic acid production by individual rat livers is demonstrated and shown to be related to the metabolism of cysteinesulfinic acid. Activity is demonstrated only in the 105000 × g supernatant of liver and cannot be shown to be present in any fraction (or combination of fractions) of heart, kidney, spleen or brain.

Glyoxylate Metabolism in Normal and Stone-Forming Humans and the Effect of Allopurinol Therapy

Summary After injection of glyoxylate-14C, detectable amounts of glyoxylate appeared in the urine for less than 1 hour. The radioactivity primarily appeared as longer persisting oxalate with a minor proportion of very transient glycolate. The rate of conversion and the proportion of the administered radioactivity recovered in 2 hours was closely similar for both normal controls and severely recurrent oxalate stone formers and was unaffected in the latter by allopurinol therapy.

Mitochondrial oxidation of cysteine.

Abstract The metabolism of [ 35 S]- and [ 14 C]cysteine by rat-liver mitochondria is described. Under certain conditions where cysteine is oxidized to cystine, sulfate production is inhibited and the inhibition is largely reversed by glutathione but not by other sulfhydryl compounds. Sulfate is the only metabolite from cysteine sulfur and pyruvate is probably the initial product of the carbon chain. An acetone-powder extract from the mitochondria is shown to have sulfate-producing activity.

The production of sulfate from cysteine without the formation of free cysteinesulfinic acid.

Abstract It has generally been accepted that the production of sulfate from cysteine (or cystine) occurs through the intermediate formation of cysteinesulfinic acid (CSA) as first postulated by Pirie (1934) . The evidence for the central role of CSA has been largely based on the demonstration that various tissue preparations readily oxidize it ( Fromageot et al., 1948 ; Medes and Floyd, 1942 ; and Singer and Kearney, 1956 ). Also, CSA has been demonstrated in normal rat brain (Begeret and Chatnagner, 1954) and S35 CSA has been isolated from tissues of rats injected with S35 cysteine ( Chapeville and Fromageot, 1955 ). However, no enzyme system has been described which is capable of producing CSA from cysteine, and CSA has not been isolated in the in vitro studies of cystine oxidation to sulfate. The present study involves a system in which S35 cysteine was oxidized to S 35 O 4 = by rat liver mitochondria under conditions where added CSA remained essentially unmetabolized. Also, there was no formation of S35 CSA while S 35 O 4 = was being actively produced. The present system seems to be of quantitative importance for the matabolism of cystine in vitro .

The chromatography of ninhydrin negative compounds on an amino acid analyzer column

Abstract The elution of 30 radioactive ninhydrin negative compounds from an amino acid analyzer column is described. Some compounds of metabolic interest are shown to be well separated on the column. The effect of CH2-groups on the elution of compounds is shown to depend on the size of the given molecule. Based on the elution of the compounds tested some calculations are made concerning the volume occupied by the resin, the water in and surrounding the resin.

S35 taurine metabolism in normal and mongoloid individuals.

Summary The metabolism of S35 taurine has been studied in normal individuals and mongols. The latter contains a group that excretes very low amounts of urinary taurine and urine from these individuals yields radiograms similar to those obtained from fasting normal individuals. These radiograms are characterized by the appearance of taurine metabolites in relatively greater amounts than taurine itself. In contrast, normal individuals after a meal produce patterns characterized by large taurine peaks compared to taurine metabolites. When administered loads of taurine, the low excretors among the mongols excrete much less of the load than do higher excretors. The low excretors behave as if deficient in body taurine.

35S 2-Hydroxyethanesulfonic Acid (Isethionic Acid) in Urine of Human Subjects Given 35S Taurine.

Summary To investigate a possible relationship between fat emboli and hypoxic decompression, rabbits were exposed to simulated altitudes of 30,000 feet and 60,000 feet in a decompression chamber. Normal rabbits, cholesterol-fed rabbits, and ethionine-treated rabbits were decompressed and autopsied, and a search was made for fat emboli in the lungs. None of the animals developed a significant number of emboli compared to control animals that were similarly treated but not decompressed. These data suggest that hypoxic decompression in the rabbit will not result in the formation of fat emboli, even in the presence of fatty liver or hyperlipemia. The factors responsible for fat emboli in fatal human decompression sickness remain unclear.

Chromatography of some cystine peptides and formation of mixed disulfides.

Abstract Chromatographic systems for cystine peptides were established and mixed disulfide formation was studied using a Technicon Amino Acid Analyzer. The ninhydrin molar color yields of peptides with N-terminal cystine was increased by splitting the disulfide bond with sodium bisulfite. Cystine peptides were prepared in the sulfhydryl form by reducing the disulfide bonds with dithiothreitol. The reduced peptides were separated from dithiothreitol on a small column of Dowex 50W X4 in the H+ form. The sulfhydryl peptides were mixed together and allowed to oxidize completely. The oxidized products were analyzed in the chromatographic system. The formation of symmetrical and mixed disulfides from the sulfhydryl compounds appeared to occur randomly.

Taurine Excretion and Intelligence in Mongolism.

Summary Significant positive associations were found between urinary taurine excretion and 2 measures of adaptive behavior, cottage placement and I.Q. scores. The correlation ratio between cottage placement and taurine excretion was Eyx = .41. I.Q. score regressed on taurine excretion yielded a coefficient of .32. Both associations are significant at the 5% level.