A new esterase for the cleavage of pivalic acid-containing prodrug esters of cephalosporins

Abstract An extracellular esterase from the actinomycetes Amycolatopsis orientalis was found by screening. It is capable of splitting the isomeric mixture (K/J) of ( I, Scheme 1 ) into 7-amino-3-methoxymethyl-3-cephem-4-carboxylic acid, pivalic acid, and acetaldehyde with a high yield. 1 The purified enzyme of 55.4 Kd by SDS-PAGE shows an n -terminal sequence of VRTCADLVRTYDLPGAVTH. The isoeletric point is 8.9 ± 0.1. It can be immobilized with good yield to VA-Epoxy Biosynth ® . Besides the above-mentioned reaction, the esterase cleaves many other esters such as methyl-2-chloropropionic acid.