Nephropathic cystinosis is a rare inherited disease characterized by cristallization of cystine in lyzosomes. Cystine accumulation caused the mutations CTNS gene encoding for cystinosine, transporter. Cystinosis commonly affects kidneys leading to renal Fanconi sysnrome during first year life, followed progressive kidney failure that necessitates initiation replacement therapy childhood or adol...

The uptake of L-cystine into cultured human umbilical vein endothelial cells has been shown to occur by a Na+-independent system which is inhibited by L-glutamate and L-homocysteine, but not by other amino acids. It is likely that the system transporting L-cystine is shared by L-glutamate. Thiol groups associated with membrane bound components appear to be essential for L-cystine uptake but it ...

1. Glutathione reductase and glutathione-cystine transhydrogenase activity in supernatant fractions of whole homogenates and homogenates of mucosal and muscular layers were determined in developing rat intestine after determination of the optimum conditions for assay of the two enzymes. In jejunum from adult rat, the K(m) values for GSSG reductase and GSH-cystine transhydrogenase activities wer...

Notable in the chemical compositi.on of the proteins of the hair (and other epidermal structures) are the high contents of cystine and sulfur (1). In a previous study (2), we have been able to demonstrate that, in the young white rat, the amount of hair produced was related to the protein (and cystine) content of the diet, but that the demands for protein (and cystine) for the growth of the hai...

FEW QUANTITATIVE ANALYSES of cystine in human serum protein fractions have been recorded in the literature, since cystine cannot be determined easily by microbiologic assay or paper chromatography. Brand and his coworkers (1, 2, 3) have reported the amount of cystine and cysteine in a few protein fractions using phosphotungstate and iodometric methods, but few results have been given using the ...

Cystinuria is manifested by cystine calculi and high urinary excretion of cystine (2), lysine, arginine (3), and ornithine (4). Abnormally low plasma levels have been established for cystine (5, 6), lysine (7), arginine, and ornithine (5, 8). Several investigators have previously demonstrated increased renal clearances for cystine, lysine, arginine, and ornithine (7-11). These four amino acids ...

In previous studies (1, 2, 3) one of us (L.) has reported experiments which are concerned with the oxidation of sulfur in the cystine molecule. It was demonstrated that if deamination of cystine be prevented by “blocking” the amino group (as in phenyluraminocystine (1) or dibenzoylcystine (3) ), the sulfur of the molecule was not oxidized normally and was excreted in the urine in large part in ...

All the serially propagated mammalian cell cultures SO far examined, as well as monkey kidney cells in primary passage, have been found to require a minimum of 13 amino acids (l-4). One of the 5 amino acids regularly required in culture, but not necessary for nitrogen balance in man, was L-cystine. In many of the experiments, however, there was definite if limited initial cellular growth in a c...

A series of b-cyclodextrin (b-CD) derivatives modified by L-cystine, including 3,30-L-cystine-bridged bis(b-CD) (2), 3-Lcystine-b-CD (3), 6,60-L-cystine-bridged bis(b-CD) (4) and 6-L-cystine-b-CD (5), were synthesised inmoderate yields by the reaction of L-cystine with mono-[2-O-(p-tolysulfonyl)]-b-CD (2-O-Ts-b-CD) or mono-[6-O-(p-tolysulfonyl)]-b-CD (6-OTs-b-CD). Their binding manners and incl...

Five cultures of Streptococcus agalactiae have an absolute requirement for L-cystine to grow in a chemically defined medium. The L-cystine could be replaced with cysteine, glutathione, or the disulfide form of glutathione. Dithiothreitol could not substitute for the sulfur-containing amino acids of glutathione; hence, the growth requirement appears to be truly nutritional. Growth was maximum wi...