Thermostable aldehyde dehydrogenase from psychrophile, Cytophaga sp. KUC-1: enzymological characteristics and functional properties

• Published in: Biochemical and biophysical research communications 2002-11, Vol.298 (5), p.632-637
• Main Authors: Yamanaka, Yuko, Kazuoka, Takayuki, Yoshida, Masahiro, Yamanaka, Kazuya, Oikawa, Tadao, Soda, Kenji
• Format: Article
• Language: English
• Subjects: Aldehyde dehydrogenase; Aldehyde Oxidoreductases - chemistry; Aldehyde Oxidoreductases - genetics; Aldehyde Oxidoreductases - metabolism; Amino Acid Sequence; Base Sequence; Catalytic Domain; Circular Dichroism; Cloning, Molecular; Cytophaga; Cytophaga - enzymology; Cytophaga - genetics; DNA, Bacterial - genetics; Enzyme Stability; Genes, Bacterial; Hydrogen-Ion Concentration; Molecular Sequence Data; NAD - chemistry; NAD - metabolism; pro-R stereospecificity; Pseudomonas aeruginosa; Psychrophile; Stereoisomerism; Substrate Specificity; Temperature; Thermostable; Transition temperature
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/S0006-291X(02)02523-8

We found the occurrence of NAD(P) +-dependent aldehyde dehydrogenase (EC1.2.1.5) in the cells of a psychrophile from Antarctic seawater, Cytophaga sp. KUC-1, and purified to homogeneity. About 50% of the enzyme activity remained even after heating at 50 °C for 65 min and the highest activity was observed in the range of 55–60 °C. The enzyme was thermostable and thermophilic, although it was derived from a psychrophile. The circular dichroism at 222 nm of the enzyme showed a peak at 32 °C. This temperature was closely similar to the transition temperature in the Arrhenius plots. The stereospecificity for the hydride transfer at C4-site of nicotinamide moiety of NADH was pro-R. The gene encoding the enzyme consisted of an open reading frame of 1506-bp encoding a protein of 501 amino acid residues. The significant sequence identity (61%) was found between the Cytophaga and the Pseudomonas aeruginosa enzymes, although their thermostabilities are completely different.