티미딜산 생성효소 활성이 높은 메토트렉세이트-내성 균주의 검색

Screening of Methotrexate-Resistant Strains with High Thymidylate Synthase Activity

Thymidylate synthase activity from extracts of various methotrexate-resistant strains was measured by spectrophotometric assay. Methotrexate-resistant strains of Lactobacillus, Pseudomonas sp., Micrococcus sp. HS-1, Klebsillela pneumonae, Cellulomonas fimi and Serratia marcescens elevated thymidylate synthase levels, especially, Pseudomonas sp. KL-9 resistant to 10-9M methotrexate have a 156-fold increase in thymidylate synthase, which suggests that Pseudomonas sp. is a convenient source of thymidylate synthase. Several methotrexate strains of yeast were tested, however, their enzyme activity was generally lower than that of bacteria tested.