Reaction of Cystine with Tryptophan under the Conditions of Acid Hydrolysis of Proteins: Mechanism of Action of Cystine
- 1 December 1979
- journal article
- research article
- Published by Oxford University Press (OUP) in Agricultural and Biological Chemistry
- Vol. 43 (12) , 2419-2423
- https://doi.org/10.1080/00021369.1979.10863835
Abstract
Heating cystine under the conditions usually used for the HCl-hydrolysis of proteins gave a small amount of bis-(2-amino-2-carboxyethyl) trisulfide (CTS). Tryptophan was greatly degraded by the reaction with CTS under these conditions. This reaction was inhibited by thioglycolic acid or hydroquinone, indicating that it involves a free-radical mechanism. The known reaction of cystine with tryptophan under the same conditions was inhibited by only thioglycolic acid. Sulfenium ion (+SCH2CH(NH2)COOH), not CTS, arising from cystine is apparently mainly responsible for loss of tryptophan during acid hydrolysis of proteins.This publication has 0 references indexed in Scilit: