Abstract
A large scale investigation of approximately 300 freshwater and 200 marine eukaryotic
algal, and 70 freshwater and 10 marine cyanobacterial cultures has been carried out
to identify the presence of protease inhibitors. Culture filtrates and methanol extracts
of algae were screened, mainly using rapid, colorimetric, microtitre plate asays,
for inhibitors of the following enzymes; carboxypeptidase A, α-chymotrypsin, collagenase,
elastase, leucine aminopeptidase, papain, and trypsin. Enzyme inhibition was detected
from 39 species of algae. The enzyme against which most inhibitors were discovered,
was papain. Almost all the activities were found in the methanol extracts. This is
the first report of the discovery of enzyme inhibitors from algae. Our results suggest
that microalgae have potential as a source of novel natural products with possible
clinical applications.