High-level production of recombinant chicken cystatin by Pichia pastoris and its application in mackerel surimi

A high level of the secreted form of recombinant chicken cystatin was expre ssed in Pichia pastoris X-33 by chromosomal integration of multiple copies of an expression cassette containing chicken cystatin under the control of glyceraldehyde-3-phosphate dehydrogenase promoter; The inhibition ability o f the recombinant for papain-like proteinase was found to correspond to tho se of natural chicken cystatin. The recombinant cystatin substantially inhi bited the proteolysis of myosin and gel softening, which consequently impro ved the gel properties of mackerel surimi.