Penicillin nontoxic in humans by first performing toxicity tests in animals and then on humans. His subsequent experiments on penicillin's response to heat and pH allowed Fleming to increase the stability of the compound. The one test that modern scientists would find missing from his work was the test of penicillin on an infected animal, the results of which would likely have sparked great interest in penicillin and sped its development by almost a decade. The importance of his work has been recognized by the placement of an International Historic Chemical Landmark at the Alexander Fleming Laboratory Museum in London on
Penicillin amidase Penicillin amidase Also called penicillin acylase. In enzymology, a penicillin amidase () is an enzyme that catalyzes the chemical reaction Thus, the two substrates of this enzyme are penicillin and HO, whereas its two products are carboxylate and 6-aminopenicillanate. This enzyme belongs to the family of hydrolases, those acting on carbon-nitrogen bonds other than peptide bonds, specifically in linear amides. The systematic name of this enzyme class is penicillin amidohydrolase. Other names in common use include penicillin acylase, benzylpenicillin acylase, novozym 217, semacylase, alpha-acylamino-beta-lactam acylhydrolase, and ampicillin acylase. This enzyme participates in penicillin and cephalosporin biosynthesis. As of late 2007,