An amino acid dependent exchange between 32P labeled inorganic pyrophosphate and ATP in microbial extracts.

摘要: Abstract An enzyme system which catalyzes a rapid, amino acid dependent exchange between inorganic pyrophosphate and ATP has been found to be ubiquitously distributed in microorganisms. The reaction is upon the presence of acids. Only leucine, isoleucine, valine, tryptophan, tyrosine, histidine, phenylalanine, methionine are active system. specific for l -form acids ATP; all other nucleotide triphosphates tested being inactive. mechanism appears involve intermediate formation aminoacyl-AMP, have low order dissociation from surface. In excess hydroxylamine trapped with corresponding hydroxamate, indicating carboxyl activation. rate 20 50 times faster than hydroxylamine. Leucyl-AMP chemically synthesized shown participate as an reaction. possible significance this protein synthesis discussed.