Title Pseudomonas putida에서 부분정제한 guanosine triphosphate cyclohydrolase 의 특성에 관한 연구
Author 김완기 · 임정빈
Address 서울대학교 자연과학대학 미생물학과
Bibliography Korean Journal of Microbiology, 20(4),201-209, 1982
Key Words Partial purification and some properties of fuanosine triphosphate cyclohydrolase from pseudomonas putida : GTP cyclohydrolase from pseudomonas
Abstract An enzyme, named GTP cyclohydorlase, that catalizes the hydrolytic removal of carbon No.8 of GTP has been partially purified from extracts of Pseudomonas putida (IAM 1506). The enzyme exists in two molecular weight forms : a high molecular weight form (150,000) and a low molecular weight from (40,000). The high molecular weight form has been purified 25-fold. Some of the properties of the enzyme are as follows : It functions optimally at pH8.0, and at 52℃. The Km value for GTP is 20uM. Divalent cations(Cd^2+ and Hg^2+) at a concentration of 5mM inhibit completely the enzyme activity. No metal ion including Mg^2+ is needed for the catalysis. The enzyme is heat labile ; its half at 57℃ is 1.5 min. Of a number of nucleotides tested, only GDP was used to any extent as substrate in place of GTP. One of the products of the enzyme is determined to be a dihydro-neopterin compound.
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