β-1,3-Glucan enhancement of protease activity in crayfish hemocyte lysate

Abstract

1. 1. A serine protease is present in crayfish haemocyte lysate, which is involved in activation of prophenoloxidase and a coagulation process. Since prophenoloxidase can be activated by β-1,3-glucans, experiments were carried out to determine if these carbohydrates exert some effect on the serine protease. 2. 2. The results showed that the serine protease can be specifically activated by the glucans and that a similar response is produced by a linear pentaose with (1 → 3)-β- d-glycosyl residues. 3. 3. The serine protease was highly specific and hydrolyzed chromogenic substrates such as Bz-Ile-Glu-( γ- O-Piperidyl)-Gly-Arg-PNA-HCl. 4. 4. The activity of the glucan-treated protease was found to be short lived, and it is suggested that this could be an important mechanism in the regulation of a coagulation process and prophenol-oxidase activation.