Reconmbinatn antibodies, especially ScFv fragments can be applied as detection reagents and even substitute for some reagents used in immunoassays such as antibodyenzyme conjugates. For ScFv fragments there is no such universal system available up to now. A vector ystem was onstructed based on pPIC9-Fc, in which the hinge, CB2 and CB3 domin (Fe fragment) of mouse IgG1 and HIS-tag wee eloned into the Pichia expression vectro pPIC9. A model SeFv was introduced into pPIC9-Fc. which can bind Gluathione-S-transfrease (GST) from Schistsoma Japonicum to yield the fusion was expreessed at high levels in the methylotrphic yeast Pichia Pastoris, secreted as a dimeric form in the culture, ad purified by Ni2+-NTA column chromatography. The expression yield can reach 10-30mg/liter of culture medium. The SeFv-Fc fusio retains the bioglogyical binding ability of the parent Scfv, and can be applied as anti-GST antibodies for the detection of GST and GST-fusion proteins. Furthermore. the successful expression and maintenance of the binding activitv verify the efficacy of the vector system for use as detection reagents in vitro, by reacting with the specific antigens and being readily detected using general anti-mouse antibodies.

Tea polyphenols, (-)-epigallocatechin galate in pariticular, were examined for their modulating effects on the drung resistance KB-A-1 cells and drug ensitive KB-3-1 cells. Both KB3-1 and KB-A-1 cells were queally sensitive to tea polyphoenol and (-)-epigallocatechin gallate. When 10μg/ml (-)-epigalllocatechin gallate or 40μg/ml tea polyphenol were persent simultaneously iwth doxorubicin, the IC50 of doxorubicin on KB-A-1 cells decreased form 10.3±0.9μg/ml to 4.2±0.2 or 2.0±0.1μg/ml. Tea polyphenol and (-)-epigalloctechin gallate enhancedthe cytotoxicity of doxorubicin on KB-A-1 cells by 5.2 and 2.5 times, respectively, but did not show a mdulating effct on KB-3-1 cells. Both tea polyphenol and (-)-epigallocatechin gallate showed reversal effects on the multidrug resistance phenotype.

Ethylglucoside monooleate was synthesized by esteriication between ethylglucoside and oleic acid with immobilized lipase from Candida antarctica in a solvent-free system. It was shouwn that a stirred tnk reactor was suitable for the enzymatic reaction process involving substrates with low miscibiligy, in which the biocatalyst was recycled five times without signiicant activity loss. Removal of the co-product, water, from thereactin medium by carrying out the reaction under reduced pressure benefited the esterification reaction and increased the monooleate yield up to 97% within 8 hours.

Ghiconobacter oxydans DSM 2003 was firstly used in the production of (R)-2-hydroxy-proionic acid through microbial oxidation of recemic 1,2-propanediol. The biotransformation was processed with high enantionmeric excess (＞99%) and near theoretical lyicld (48% of racemic 1,2-propanediol) when the substrate concentration was lower than 20g/L. When the substrate concentration was increased. maintaining the pH at 6.0 helped to improve the enantionselectivity.

Propyl-glycoside lacter, a new α-hydroxy acids derivative, was synthesized byesterification between lactic acid and propl-glycoside, instead oftransesteritication as reported previously, in a non-aqeous medium using immobilxed lipase as biocatalyst. A con ersion of 66% was achieved by the optimixation o the reaction conditions. Lipase activitywas found to be reduced when exposed to high conccentration mechanism of the enzymtic esterfication reaction. Additon of molecular sieves eliminated hydrolysis of the produced ester and allowed glycoside conversion rising to 75%