Analysis of the protein pattern of Gremmeniella abietina with special reference to protease activity

Abstract

Gremmeniella abietina is the causative agent in Scleroderris canker of conifers. This fungus grows very slowly and thus its protein pattern may be difficult to obtain, especially since fungal protease activities are unknown. We show that the protease activity is very low in young cultures grown in Campbell's V8 juice liquid medium but degraded some of the protein bands making it very difficult to reliably compare electrophoretic protein pattern from sample to sample. A calcium- and zinc-dependent metalloprotease activity was specifically detected, and it was inhibited by ethyl-enediaminetetraacetate and o-phenanthroline at a neutral pH. Other protease activities may be present since inhibition of the proteolytic activity by p-chloromercuribenzoate and pepstatin was also seen. Phenylmethanesulfonyl fluoride showed only minimal inhibitory effect. The fungal protein patterns were reproducible with only small intensity differences between different culture batches. The protein pattern resembled that of Sirococcus strobilinus, but immunoblotting with anti-Gremmeniella antibody showed no cross-reactivity and thus Sirococcus may not be closely related to Gremmeniella.

Key Words:

• Ascocalyx
• Gremmeniella
• immunotyping
• protease
• Sirococcus