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Peptide uptake in germinating barley embryos involves a dithiol‐dependent transport protein
Author(s) -
Walker Smith David J.,
Payne John W.
Publication year - 1983
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(83)80929-6
Subject(s) - dithiothreitol , dithiol , phenylarsine oxide , peptide , chemistry , biochemistry , endosperm , reagent , thiol , enzyme , organic chemistry
An active transport system for small peptides occurs in the scutellar membrane of germinating barley and serves to move the products of partial hydrolysis of storage proteins from the endosperm into the growing embryo. Transport of peptides, but not amino acids or glucose, is inhibited by the thiol reagents, N ‐ethylmaleimide and p ‐chloromercuribenzene sulphonic acid (PCMBS). Peptide substrates protect against PCMBS inactivation. The dithiol‐specific reagent, phenylarsine oxide (PAO) also inhibits. The reducing agent, dithiothreitol, reverses the inactivation caused by PCMBS and PAO. We conclude that the peptide transport system contains a redox‐sensitive, dithiol‐dependent protein.