Cyclization of .DELTA.-(L-.ALPHA.-aminoadipyl)-L-cysteinyl-D-valine to penicillins by cell-free extracts of Streptomyces clavuligerus.

Abstract
Cell-free extracts prepared by sonication of S. clavuligerus cyclized .delta.-(L-.alpha.-aminoadipyl)-L-cysteinyl-D-valine (ACV) into a penicillin-type antibiotic. The antibacterial spectrum of this antibiotic suggested it was a mixture of isopenicillin N and penicillin N indicating that cyclization and racemase activities were present. Cyclization activity was optimal in extracts prepared from 48 h cultures. Extracts incubated at 20.degree. C produced antibiotic for 2 h before activity ceased. Cyclization activity showed an absolute requirement for dithiothreitol (DTT) and O2 and was stimulated by ascorbic acid and FeSO4. No requirement for ATP was observed.

This publication has 20 references indexed in Scilit: