SERINE PROTEINASE-INHIBITORS FROM INSECT HEMOLYMPH

Insect hemolymph, like vertebrate serum, contains several different ty pes of polypeptides that are able to inhibit the catalytic function of proteolytic enzymes, however studies on proteins possessing this capa bility have been limited to a relatively few species. A comparative ex amination of the inhibition of trypsin, chymotrypsin, neutrophil elast ase and cathepsin G and pancreatic elastase by the hemolymph of 14 ins ect species belonging to six orders showed great diversity in terms of both total proteinase inhibitory capacity and specificity. Most of th e inhibitors examined fall into two groups: low molecular mass protein s (below 10 kDa) related to Kunitz type inhibitors, and proteins of ab out 45 kDa which belong to the serpin superfamily of serine proteinase inhibitors. This minireview describes the properties, characteristics and possible biological significance of selected inhibitors.