ABSTRACT
A racemic glycidyl butyrate resolving strain, preliminarily identified as a Rhizopus sp., had been isolated from soil. Its extracellular lipase was found to enantioselectively hydrolyze the (S)-enantiomer of the chiral ester, with optimal activities at pH 5.3 and 42 degrees C. Higher enantioselectivity of the enzyme was observed at lower temperatures, while the best enantioselectivity was obtained at pH 5.5-6.0, with an E value (enantiomeric ratio) of 57.
Subject(s)
Butyrates/metabolism , Lipase/metabolism , Rhizopus/classification , Rhizopus/enzymology , Enzyme Activation , Enzyme Stability , Hydrogen-Ion Concentration , Hydrolysis , Mycelium/classification , Mycelium/metabolism , Reproducibility of Results , Sensitivity and Specificity , Soil Microbiology , Species Specificity , Stereoisomerism , TemperatureABSTRACT
35 of the total products of galacto-oligosaccharide (GOS) could be obtained from the two-phase system with cyclohexane and ethyl acetate as bulk organic phases and 15% phosphate buffer as aqueous phase. The effects of temperature pH of buffer lactose concentration galactose and glucose and the immobilization of enzyme on the synthesis of GOS were studied. It was found that the reaction temperature and initial lactose concentration didn'thave obvious effects while the addition of glucose and galactose somewhat affected the GOS yield and the GOS yields could reach 64.78% with lactase immobilized on resin D345.
ABSTRACT
The fragments of the androgen receptor (amino acids: 359-732) and of the glucocorticoid receptor (amino acids: 396-548) were expressed in E. coli as fusion proteins with GST. Both fusion proteins, denoted GST-AR and GST-GR, contained the DNA-binding domain and some flanking amino acids. In gel retardation assay both fusion proteins could bind the androgen/glucocorticoid response element (ARE/GRE). We found that both cytosol and nuclear extracts from rat ventral prostate (v.p), but not from other source tested could abolish the interaction of GST-AR and GST-GR with ARE/GRE (from C3 (1) gene and MMTV LTR). The inhibition was androgen-dependent and sensitive to temperature and trypsin treatment. It implies that a protein inhibitor was present in the rat ventral prostate.
