Open AccessCarp Insulin: Amino Acid Sequence, Biological Activity and Structural Properties
Author(s) -
MAKOWER Alexander,
DETTMER Rudolf,
RAPOPORT Tom A.,
KNOSPE Siegfried,
BEHLKE Joachim,
PREHN Siegfried,
FRANKE Peter,
ETZOLD Gerhard,
ROSENTHAL Sinaida
Publication year - 1982
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1982.tb05886.x
Subject(s) - carp , circular dichroism , insulin , amino acid , cyprinus , peptide sequence , dimer , biochemistry , biology , chemistry , threonine , serine , endocrinology , fish <actinopterygii> , gene , enzyme , organic chemistry , fishery
The amino acid sequence of insulin of carp ( Cyprinus carpio ) has been determined and correlated with its biological activity in a fat‐cell test and its structural properties as measured by circular dichroism and sedimentation analysis. The amino acid sequence of carp insulin displays some unusual features: the B chain is longer at the N ter‐ minus by two residues as compared with mammalian insulins and there are substitutions of the charged residues, found in most insulins at positions B21 and B22, by proline and threonine respectively. On the other hand, all amino acid residues essential for biological activity and for the association of insulin monomers are the same in carp insulin. Accordingly, the half‐maximal response in a fat‐cell test is reached with carp insulin at concentrations which are only three times higher than with porcine insulin and the maximal response is the same. The circular dichroism spectrum of carp insulin resembles greatly that of bovine insulin indicating that it has a similar spatial structure. Despite amino acid substitutions in the dimer‐dimer contact region, carp insulin is able to form hexamers.