MICROBIAL TRANSFORMATION OF IMMUNOSUPPRESSIVE COMPOUNDS .3. GLUCOSYLATION OF IMMUNOMYCIN (FR-900520) AND FK-506 BY BACILLUS-SUBTILIS ATCC-55060

The regiospecific glucosylation of FK 506 and immunomycin (FR 900520) at the 24-hydroxy position was performed using resting cells of Bacill us subtilis ATCC 55060. 24-Glucopyranosyl FK 506 and 24-glucopyranosyl immunomycin were isolated by methylene chloride extraction and purifi cation using reverse phase HPLC. The metabolite structures were establ ished using spectroscopic techniques including MS and NMR. The glucose conjugate was further confirmed by chemical degradation. Enzymatic gl ucosylation was demonstrated using cell-free extracts derived from Bac illus subtilis ATCC 55060. The 24-glucosyltransferase, which appears U DP-glucose dependent, was solubilized from cell membranes by treatment with 0.1% Nonidet P-40 detergent. The optimal conditions for assay fo r the enzyme have been determined.