Expression of a cholesterol oxidase gene from Arthrobacter simplex in Escherichia coli and Pichia pastoris

摘要

The gene (choA_A),encoding cholesterol oxidase from Arthrobacter simplex F2,was cloned and sequenced by polymerase chain reaction.The gene consists of 1653 base pairs and encodes a protein of 551 amino acids (aa).N-terminal sequence analysis of the extracellular cholesterol oxidase of A.simplex F2 confirmed that the mature enzyme consists of 502 aa with a predicted molecular mass of 54,269 Da,and is translated with a 49 aa signal sequence.The structure gene for ChoA_A was cloned and expressed efficiently in Escherichia coli and Pichia pastoris.The deletion of the choA_A signal sequence was favorable for the expression of extracellular cholesterol oxidase by P.pastoris.