Key Laboratory of Ecology and Biological Resources in Yarkand Oasis at Universities under the Education Department
of Xinjiang Uygur Autonomous Region, Department of Kashi Normal College, No.29. Xueyuan Road, Kashi Prefecture,
Xinjiang Uygur Autonomous Region, China.
7-amino cephalosporanic acid (7-ACA) is the crucial intermediate for the synthesis of semi-synthetic antibiotics,
which is currently prepared by two-step biocatalysis using D-amino acid oxidase and glutaryl-7-amino cephalosporanic
acid acylase (GL-7-ACA acylase) starting from cephalosporin C (CPC). Compared with the two-step enzymatic
method, one-step method is more efficient and economical. But, the available Cephalosporin C acylase (CPC acylase) always
take glutaryl-7-amino cephalosporanic acid (GL-7-ACA) as their primary substrate, and have low catalytic activities
towards CPC to be used in industry. We investigated the catalytic mechanism of CPC acylase by the sequence alignment,
homology modeling, and active site analysis to a series of CPC acylases from Pseudomonas where some effective mutations
have been reported for activity enhancement. Two CPC acylases coded by the genes acyII and S12 are studied intensively
for the interaction between the amino acid residues in the activity region and the substrate CPC based upon the
complex structure obtained from the homology modeling and molecular docking. Furthermore, the catalytic parameters of
the two CPC acylases were measured experimentally in order to corroborate the modeling analysis and propose potential
designing strategy for improvement of enzymic activity.