Open AccessBoar acrosin is a two‐chain molecule
Author(s) -
FOCKNÜZEL Roselinde,
LOTTSPEICH Friedrich,
HENSCHEN Agnes,
MÜLLERESTERL Werner
Publication year - 1984
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1984.tb08211.x
Subject(s) - acrosin , immunoglobulin light chain , serine , chemistry , biochemistry , peptide sequence , protein primary structure , amino acid , zymogen , residue (chemistry) , stereochemistry , enzyme , biology , antibody , genetics , semen , acrosome , gene , immunology
Acrosin (EC 3.4.21.10), the major proteinase of mammalian spermatozoa, has been demonstrated to be a two‐chain glycoprotein with an M r ‐4200 light chain covalently attached to an M r ‐37000 heavy chain. Following mercaptolysis of the disulfide bonds, the two chains were separated by high‐performance liquid chromatography on a reversed‐phase column. Sequence analysis of the isolated light chain (23 amino acid residues) indicated a considerable sequence homology with the bovine chymotrypsinogen activation peptide (6 out of 15 positions with identical amino acids, i.e. 40% identity) and the pro‐part of other serine proteinases (17–22% identity), thus suggesting that the acrosin light chain corresponds to the pro‐part of the acrosin zymogen. In position 3, the light chain confers a carbohydrate side chain N ‐glycosidically linked to the acceptor sequence Asn‐Xaa‐Thr. Evidence is presented that the acrosin light chain is connected via two disulfide bridges to the heavy chain which contains about 320 amino acids including the active‐site residues of the proteinase.