Enzymes Hydrolysing L-Leucyl-β-Naphthylamide and α-L- Aspartyl- p-Nitroanilide in Human Placenta during Development

Abstract

Activities of L-leucyl-β-naphthylamidase (aminoacyl-naphthylamide amidohydrolase EC 3.4.1.1), and α-L-aspartyl-p-nitroanilide hydrolase of placenta and related tissues were determined in 4 periods of the development of human placenta. It was shown that both enzymes were the most active in placentas originating from the period of growth and differentiation, i.e., between the 14th and 28th week of gestation. Three zones of L-leucyl-β-naphthylamidase were demonstrated by polyacrylamide gel electrophoresis in extracts of placenta, and four zones in membranes. Placenta was found to contain one zone of a-Laspartyl- naphthylamidase, membranes were devoid of this activity.