Open AccessLimited Proteolysis of Tryptophanyl‐tRNA Synthetase from Beef Pancreas
Author(s) -
EPELY Sylvie,
GROS Claude,
LABOUESSE Julie,
LEMAIRE Geneviève
Publication year - 1976
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1976.tb10004.x
Subject(s) - proteolysis , biochemistry , subtilisin , chymotrypsin , protease , enzyme , tryptophan , trypsin , papain , amino acid , chemistry , transfer rna , proteases , cleavage (geology) , biology , stereochemistry , rna , gene , paleontology , fracture (geology)
Treatment of purified tryptophanyl‐tRNA synthetase with either chymotrypsin, papain, subtilisin or elastase converts all the enzyme into a high‐molecular‐weight intermediate. This protease‐resistant core molecule has the same dimeric structure as the native protein and possesses the ability to bind substrates (tryptophan, ATP and tRNA Trp ) but is catalytically inactive. The monomer molecular weight of the protease‐treated enzyme is 39000 compared to 54000 for the intact molecule. Chemical studies indicate that proteases excise the amino‐terminal part of the polypeptide chain. It has been demonstrated previously that removal of a 13000‐dalton fragment from the amino‐terminal region of the tryptophanyl‐tRNA synthetase converts the native enzyme to another active form. Cleavage of 20 additional amino acids produces the inactive protease‐resistant core.