Identification of protein kinase C isoforms in marine mussels.

In this paper we have examined the distribution of some isoforms of protein kinase C in different tissues from the sea mussel Mytilus galloprovincialis Lmk.. By immunoblot analysis, we have detected the presence of at least three PKC isoforms, all preferably associated with the cellular cytosolic fraction. The Ca(2+)-independent form PKC delta was separated from the Ca(2+)-dependent forms (PKC alpha and beta) by means of an ionic change chromatography on DE-52. A comparative study was carried out on the phosphorylatable non-artificial substrates. The M.B.P. protein proved to be the best substrate, while the worst was HIIIS histone which, however, is frequently used in evaluation assays of the activity.