Pearce C J, Barnett J E, Anthony C, Akhtar M, Gero S D
Biochem J. 1976 Dec 1;159(3):601-6. doi: 10.1042/bj1590601.
By using wild-type and deoxystreptamine-negative mutants of Streptomyces fradiae grown in media containing [6(-3)H]glucose or [U-14C]glucose, and by subsequent hydrolysis of the labelled neomycin produced, neamines labelled with 3H in both rings I and II, but with 14C in ring I only, were prepared. A mixture of these two forms of neamine was converted by deoxystreptamine-negative Streptomyces rimosus forma paromomycinus into neomycin (not paromomycin) with a 30% yield. The3H: 14C ratio in this neomycin was the same as the measured in neamine produced by hydrolysis of the neomycin, and in unused neamine reisolated from the incubation medium. The 3H:14C ratio in the neomycin was not affected by the presence of unlabelled deoxystreptamine during the incubation. The radioactivity in the neomycin was associated with rings I and II only. It is concluded that the added neamine is incorporated into antibiotic intact, without initial hydrolysis, and that the probable first step in the subunit assembly of neomycin is the formation of neamine.
通过使用在含有[6(-3)H]葡萄糖或[U-14C]葡萄糖的培养基中生长的野生型和去氧链霉胺阴性突变型弗氏链霉菌，并通过随后对产生的标记新霉素进行水解，制备了在环I和环II中都用3H标记但仅在环I中用14C标记的新霉胺。这两种形式的新霉胺的混合物被去氧链霉胺阴性的龟裂链霉菌副伤寒亚种转化为新霉素（而非巴龙霉素），产率为30%。该新霉素中的3H:14C比率与新霉素水解产生的新霉胺中以及从培养培养基中重新分离出的未使用的新霉胺中测得的比率相同。新霉素中的3H:14C比率在培养期间不受未标记的去氧链霉胺存在的影响。新霉素中的放射性仅与环I和环II相关。得出的结论是，添加的新霉胺完整地掺入抗生素中，没有初始水解，并且新霉素亚基组装中可能的第一步是新霉胺的形成。
