Premium
The prohormone processing activity is enriched in a low‐density subpopulation of chromaffin granules
Author(s) -
Maret Gérard E.,
Fauchère Jean-Luc
Publication year - 1986
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(86)80171-5
Subject(s) - prohormone , differential centrifugation , centrifugation , chemistry , in vitro , biochemistry , proteolysis , enzyme , peptide , biology , hormone
Bovine adrenomedullary chromaffin granules can be separated into two subpopulations by differential centrifugation. The subpopulation which sediments at the interface of two sucrose layers, 1.6 and 1.8 M respectively, is found to be enriched about 10‐times in prohormone processing activity, as measured by in vitro degradation of synthetic peptide substrates. The enhanced proteolytic activity is not due to lysosomal contaminations which are very low and only slightly increased in the more active fraction. The low density of the enriched subpopulation suggests that we are dealing with immature granules. The physiological implications of this finding are discussed. Furthermore, the enriched fraction can be used as the starting material for the isolation ofproenkephalin processing enzymes.