title: Production and Purification of d-Aminoacylase from Alcaligenes denitrificans and Taxonomic Study of the Strain.
abstract: A d-aminoacylase-producing microorganism, strain DA181, isolated from soil was identified as Alcaligenes denitrificans subsp. denitrificans. This strain produced about 29,300 units (micromoles of product formed per hour) of d-aminoacylase and 2,300 units of l-aminoacylase per gram of cells (wet weight) when cultivated in a medium containing 1% N-acetyl-dl-leucine as the carbon source. The d-aminoacylase was purified 345-fold. The specific activity of the purified enzyme was 108,600 units per mg of protein when N-acetyl-d-methionine was used as a substrate. The apparent molecular weight was 58,000, as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. N-Acetyl-d-methionine was the favored substrate, followed by N-acetyl-d-phenylalanine. This enzyme had a high stereospecificity, and its hydrolysis of N-acetyl-l-amino acids was almost negligible.
authors.affiliation: Institute of Biochemistry, National Yang-Ming Medical College, Taipei, Taiwan 11221, Republic of China.
authors.forename: Y C
authors.initials: YC
authors.lastname: Tsai
authors.forename: C P
authors.initials: CP
authors.lastname: Tseng
authors.forename: K M
authors.initials: KM
authors.lastname: Hsiao
authors.forename: L Y
authors.initials: LY
authors.lastname: Chen