| abstract |
A mutant cephalosporin C acylase ("CC acylase") of the formula (as its precursor before processing the said precursor form into α-subunit and β-subunit thereof in a host cell): n n A¹⁻²⁶⁸-X¹-Tyr-X²-A²⁷²⁻³⁰⁴-X³-A³⁰⁶⁻⁷⁷³ n n n wherein A¹⁻²⁶⁸ is the same amino acid sequence as that from Thr¹ to Gly²⁶⁸ of native CC acylase, n A²⁷²⁻³⁰⁴ is the same amino acid sequence as that from Gln²⁷² to Tyr³⁰⁴ of native CC acylase, n A³⁰⁶⁻⁷⁷³ is the same amino acid sequence as that from Val³⁰⁶ to Ala⁷⁷³ of native CC acylase, n X¹ is Met or other amino acid, n X² is Ala or other amino acid and n X³ is Cys or other amino acid, n providing that when X¹ is Met and X² is Ala, n X³ is an amino acid other than Cys. n A DNA coding for the CC acylase is also provided, together with an expression vector containing the said DNA and a microorganism transformed with the said expression vector. The CC acylase is produced by culturing the said transformed microorganism in an aqueous nutrient medium. |