title: [Molecular form and stability of D-hydantoinase deleted at C-terminal residue Arg].
abstract: This report is about only deleting one C-terminal residue of D-hydantoinase to result in obvious changes on its molecular form and stability. A recombinant D-hydantoinase (P479) and its mutant enzyme deleted at C-terminal residue Arg (P478) were prepared by methods of gene cloning, expression and purification. Results show that the subunit molecular weight of P479 and P478 is the same (54kDa) as determined by SDS-PAGE, whilst the molecular form of native P479 and P478 is a dimer and a monomer respectively in the completely operative conditions. Compared with P479, the enzymatic activity of P478 for substrate hydantoin maintained about 40% and pH stability was obviously increased, at the alkaline side in particular, as well as the anti-SDS ability was also raised. However, the thermal stability for P478 was clearly lowed as compared to P479. It implies from above data that the C-terminal residue Arg of the D-hydantoinase is a crucial one for subunit dissociation, but non-essential for catalysis.
authors.affiliation: Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of National Ministry of Education, Shanxi University, Taiyuan 030006, China.
authors.forename: Li-xi
authors.initials: LX
authors.lastname: Niu
authors.forename: Xue-yao
authors.initials: XY
authors.lastname: Zhang
authors.forename: Ya-wei
authors.initials: YW
authors.lastname: Shi
authors.forename: Jing-ming
authors.initials: JM
authors.lastname: Yuan
mesh_terms: D000581:Amidohydrolases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D009154:Mutation; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000302:isolation & purification; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D013696:Temperature
chemical_list: D011994:Recombinant Proteins; D012967:Sodium Dodecyl Sulfate; D000581:Amidohydrolases; C020047:dihydropyrimidinase