Chloroquine and Synthesis of Aminoacyl Transfer Ribonucleic Acids. Tryptophanyl Transfer Ribonucleic Acid Synthetase of Escherichia coli and Tryptophanyladenosine Triphosphate Formation

Karl H. Muench

Research output: Contribution to journalArticle

12 Scopus citations

Abstract

The antimalarial drug, chloroquine, enhances both the rate and extent of enzymatic charging of tryptophan to transfer ribonucleic acid of Escherichia coli. The effect occurs throughout a 230-fold purification of tryptophanyl transfer ribonucleic acid synthetase. Chloroquine does not affect the rate of tryptophan-dependent adenosine triphosphate-[32P]inorganic pyrophosphate exchange. Although the synthetase forms tryptophanyladenosine triphosphate ester in addition to tryptophanyl transfer ribonucleic acid, chloroquine does not significantly affect formation of the tryptophanyladenosine triphosphate. Chloroquine changes neither the Km nor the Vmax for the active form of tryptophan transfer ribonucleic acid. The effect of chloroquine on reaction rate can be attributed entirely to its conversion of the inactive form of tryptophan transfer ribonucleic acid into the active form when the latter is at suboptimal concentration. The inactive form of tryptophan transfer ribonucleic acid is not an inhibitor of the enzyme.

Original languageEnglish (US)
Pages (from-to)4872-4879
Number of pages8
JournalBiochemistry
Volume8
Issue number12
DOIs
StatePublished - Dec 1 1969

ASJC Scopus subject areas

  • Biochemistry

Fingerprint Dive into the research topics of 'Chloroquine and Synthesis of Aminoacyl Transfer Ribonucleic Acids. Tryptophanyl Transfer Ribonucleic Acid Synthetase of Escherichia coli and Tryptophanyladenosine Triphosphate Formation'. Together they form a unique fingerprint.

  • Cite this