Aminopeptidase P from bovine lung: solubilization, properties, and potential role in bradykinin degradation.

Aminopeptidase P was solubilized from bovine lung by sodium deoxycholate extraction of salt-washed, delipidated lung acetone powders. Hydrolysis of the standard aminopeptidase P substrate, Gly-Pro-Hyp, as well as cleavage of Arg-Pro-Pro and the Arg1-Pro2 bond of bradykinin, co-eluted from a Mono Q anion exchange column and demonstrated identical inhibitory profiles suggesting that all activities were functions of the same enzyme. The metal chelator, 1,10-phenanthroline, completely inhibited activity suggesting that aminopeptidase P is a metallopeptidase.

Investigations on myelination in vitro: IV. "Myelin-like" or premyelin structures in cultures of dissociated brain cells from 14--15-day-old embryonic mice.

The present study reports ultrastructural and biochemical data characteristic of myelin-related structures in 30- to 41-day-old cultures of dissociated brain cells from 14- to 15-day-old embryonic mice. Multilayered membranous material was identified and displayed an alternation of electron-lucent and electron-dense lamellae with a periodicity of 102 A. In these membranes, typical myelin constituents like basic protein, cerebrosides, sulfatides, and CNPase could be identified.