title: Enhanced synthesis of L-threo-3,4-dihydroxyphenylserine by high-density whole-cell biocatalyst of recombinant L-threonine aldolase from Streptomyces avelmitilis.
abstract: L-threo-3,4-Dihydroxyphenylserine (DOPS) is a chiral unnatural beta-hydroxy amino acid used for the treatment of Parkinson disease. We developed a continuous bioconversion system for DOPS production that uses whole-cell biocatalyst of recombinant Escherichia coli expressing L-threonine aldolase (L-TA) genes cloned from Streptomyces avelmitilis MA-4680. Maximum conversion rates were observed at 2 M glycine, 145 mM 3,4-dihydroxybenzaldehyde, 0.75% Triton-X, 5 g E. coli cells/l, pH 6.5 and 10 degrees C. In the optimized condition, overall productivity was 8 g/l, which represents 40 times the synthesis yield possible with no optimization of conditions.
authors.affiliation: Department of Food Science and Human Nutrition, Chonbuk National University, Jeonju, Jeonbuk, 561-756, South Korea. baiksh@chonbuk.ac.kr
authors.forename: Sang-Ho
authors.initials: SH
authors.lastname: Baik
authors.forename: Hideki
authors.initials: H
authors.lastname: Yoshioka
mesh_terms: D000978:Antiparkinson Agents / Q000378:metabolism*; D001547:Benzaldehydes / Q000378:metabolism; D001709:Biotechnology / Q000379:methods*; D002396:Catechols / Q000378:metabolism; D015103:Droxidopa / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005998:Glycine / Q000378:metabolism; D012696:Glycine Hydroxymethyltransferase / Q000235:genetics / Q000378:metabolism*; D013302:Streptomyces / Q000201:enzymology* / Q000235:genetics; D013912:Threonine / Q000378:metabolism*
chemical_list: D000978:Antiparkinson Agents; D001547:Benzaldehydes; D002396:Catechols; D013912:Threonine; C005581:protocatechualdehyde; D012696:Glycine Hydroxymethyltransferase; D015103:Droxidopa; D005998:Glycine