Masahiko Goda

The catalytic mechanism of amidase also involves nitrile hydrolysis

The amidase from Rhodococcus rhodochrous J1, which hydrolyzes an amide to an acid and ammonium, was surprisingly found to catalyze the hydrolytic cleavage of the C‐N triple bond in a nitrile to form an acid and ammonium stoichiometrically. The amidase exhibited a K m of 3.26 mM for benzonitrile in contrast to that of 0.15 mM for benzamide as the original substrate, but the V max for benzonitrile was about 1/6000 of that for benzamide. A mutant amidase containing alanine instead of Ser195, which is essential for amidase catalytic activity, showed no nitrilase activity, demonstrating that this residue plays a crucial role in the hydrolysis of nitriles as well as amides.

Discovery of a Novel Enzyme, Isonitrile Hydratase, Involved in Nitrogen-Carbon Triple Bond Cleavage

Isonitrile containing an N≡C triple bond was degraded by microorganism sp. N19-2, which was isolated from soil through a 2-month acclimatization culture in the presence of this compound. The isonitrile-degrading microorganism was identified asPseudomonas putida. The microbial degradation was found to proceed through an enzymatic reaction, the isonitrile being hydrated to the corresponding N-substituted formamide. The enzyme, named isonitrile hydratase, was purified and characterized. The native enzyme had a molecular mass of about 59 kDa and consisted of two identical subunits. The enzyme stoichiometrically catalyzed the hydration of cyclohexyl isocyanide (an isonitrile) to N-cyclohexylformamide, but no formation of other compounds was detected. The apparent K m value for cyclohexyl isocyanide was 16.2 mm. Although the enzyme acted on various isonitriles, no nitriles or amides were accepted as substrates.

Optimum Culture Conditions for the Production of N-Substituted Formamide Deformylase by Arthrobacter pascens F164

We investigated the optimum culture conditions for the production of a novel enzyme, N-substituted formamide deformylase, which acts mainly on N-benzylformamide, in Arthrobacter pascens F164. The highest enzyme activity was obtained when this strain F164 was cultivated in a synthetic medium with N-benzylformamide as sole nitrogen source. This deformylase was found to be an inducible enzyme depending on N-benzylformamide.

Erratum to: The catalytic mechanism of amidase also involves nitrile hydrolysis (FEBS 21159): [FEBS Letters 439 (1998) 325-328]1

FEBS 21443 15-2-99 FEBS 21495 Corrigendum to: GD1K-replica peptides functionally mimic GD1K, an adhesion molecule of metastatic tumor cells, and suppress the tumor metastasis (FEBS 21260) [FEBS Letters 441 (1999) 20^21]1 Dai Ishikawa, Hironori Kikkawa, Koichi Ogino, Yoshio Hirabayashi, Naoto Oku, Takao Taki* Cellular Technology Institute, Otsuka Pharmaceutical Co. Ltd., 463-10 Kagasuno, Kawauchi, Tokushima 771-0192, Japan Department of Radiobiochemistry, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan Institute of Physical and Chemical Research, RIKEN, Hirosawa 2-1, Wako, Saitama 351-0198, Japan

Erratum to: The catalytic mechanism of amidase also involves nitrile hydrolysis (FEBS 21159): [FEBS Letters 439 (1998) 325–328]1PII S0014-5793(98)01406-91

FEBS 21443 15-2-99 FEBS 21495 Corrigendum to: GD1K-replica peptides functionally mimic GD1K, an adhesion molecule of metastatic tumor cells, and suppress the tumor metastasis (FEBS 21260) [FEBS Letters 441 (1999) 20^21]1 Dai Ishikawa, Hironori Kikkawa, Koichi Ogino, Yoshio Hirabayashi, Naoto Oku, Takao Taki* Cellular Technology Institute, Otsuka Pharmaceutical Co. Ltd., 463-10 Kagasuno, Kawauchi, Tokushima 771-0192, Japan Department of Radiobiochemistry, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan Institute of Physical and Chemical Research, RIKEN, Hirosawa 2-1, Wako, Saitama 351-0198, Japan

Erratum to: The catalytic mechanism of amidase also involves nitrile hydrolysis (FEBS 21159)

FEBS 21443 15-2-99 FEBS 21495 Corrigendum to: GD1K-replica peptides functionally mimic GD1K, an adhesion molecule of metastatic tumor cells, and suppress the tumor metastasis (FEBS 21260) [FEBS Letters 441 (1999) 20^21]1 Dai Ishikawa, Hironori Kikkawa, Koichi Ogino, Yoshio Hirabayashi, Naoto Oku, Takao Taki* Cellular Technology Institute, Otsuka Pharmaceutical Co. Ltd., 463-10 Kagasuno, Kawauchi, Tokushima 771-0192, Japan Department of Radiobiochemistry, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan Institute of Physical and Chemical Research, RIKEN, Hirosawa 2-1, Wako, Saitama 351-0198, Japan