ON THE DEVELOPMENT OF INCREASED TRYPTOPHAN SYNTHETASE ENZYME ACTIVITY BY CELL-FREE EXTRACTS OF NEUROSPORA CRASSA

Abstract

A cell-free extract from conidia of Neurospora crassa developed increased tryptophan synthetase activity when incubated with a mixture of amino acids, a source of energy, and inorganic salts. Fifteen individual acids were required for development of maximal increases of enzymic activity. Either hexose diphosphate or adenosine triphosphate could serve as energy source. Diphosphopyridine nucleotide, polyvinyl acetate, and magnesium and calcium ions were required. The addition of ribonuclease enzyme, ethionine, fluorophenylalanine, thienylalanine, or various antibiotics prevented development of increased tryptophan synthetase activity. The increase of activity was accompanied by a net synthesis of protein.