Open AccessGramicidin S Synthetase
Author(s) -
GADOW Andŕ,
VATER Joachin,
SCHLUMBOHM Wihelm,
PALACZ Zbigniew,
SALNIKOW Johann,
KLEINKAUF Horst
Publication year - 1983
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1983.tb07352.x
Subject(s) - thioester , tripeptide , gramicidin s , chemistry , stereochemistry , hydrolysis , enzyme , gramicidin , reaction intermediate , amino acid , biochemistry , catalysis , membrane
The reactive thioester complees of gramicidin S synthetase with substrate amino acids and intermediate peptides are slowly hydrolyzed in neutral buffer solutions under mild conditions. Fully active enzyme is recoverd. These processes are strongly accelerated by certain thiol protective agents. In the preesence of 1 mM dithieoerythritol the half‐life times of sthese hydrolysis reactions are in the range of 1–90 h at 3 °C. The thieoester comple of gramicidin S synthetase 2 (GS2, the heavy enzyme) with the tripeptide D Phe‐Pro‐Val is distinguished by the highest stability of all these intermediates. A different decomposition pattern is observed for the thioester comple of GS2 with L Orn. Here 3‐amino‐2‐piperidone ( cyclo ‐ L Orn0 is formed in a rapid cyclization reaction. This product specifically blocks the activation center of GS2 for L Orn at the thioester buinding site. All other activation reactions of g ramicidin S synthetase are unaffected. A procedure for a specific labelling of the reaction centers of the multienzyme is outlined.