Wild-type biocatalysts usually show high activity and selectivity towards their native substrates. Since non-native substrates are often used in synthetically useful biocatalytic transformations, it is necessary to engineer enzymes for improved activity, stability and selectivity (chemo-, regio- and stereoselectivity). Herein we give an overview of the recent advances in engineering the enantioselectivity of biocatalysts, with an aim to stimulate further development of this important field in China.
Animals ; Biocatalysis ; Epoxide Hydrolases ; genetics ; metabolism ; Esterases ; genetics ; metabolism ; Humans ; Lipase ; genetics ; metabolism ; Protein Engineering ; methods ; Stereoisomerism

OBJECTIVETo explore genetic relationships of the 39 materials in six species of Curcuma.

METHODThe peroxidase isozyme (POD) and esterase isozyme (EST) were studied using vertical slab polyacrylamide gel electrophoresis (PAGE) technique, and the zymograms were analyzed using the software of NTSYSpc2. 1.

RESULTThe interspecific zymogramatic differences were obvious. Each species possessed its own specific zymogram distinguishing form the others. In the analysis of EST isozyme, C. phaeocaulis, C. wenyujin, C. kwangsiensis and C. chuanhuangjiang had their own specific zymogram. In the analysis of POD isozyme, just C. phaeocaulis and C. kwangsiensis had their specific zymogram.

CONCLUSIONThe genetic relationships are not associated with the geographical distributions and the genetic relationship between C. longa and C. sichuanensis are very close.

Cluster Analysis ; Curcuma ; classification ; enzymology ; genetics ; Electrophoresis, Polyacrylamide Gel ; Esterases ; analysis ; genetics ; Isoenzymes ; analysis ; genetics ; Peroxidase ; analysis ; genetics ; Phylogeny ; Species Specificity

OBJECTIVETo investigate the genotypes , allele frequencies and dynamic distribution on resistance associated esterase genes of Culex pipiens complex in Hangzhou.

METHODSThe PCR-restriction fragment length polymorphism (PCR-RFLP) assay was applied to type the resistance associated esterase genes, and dynamic surveillance on frequencies of the resistance associated esterase gene of natural population of Culex pipiens complex in Hangzhou during 2003-2005, and phenotype of the resistance associated esterase genes were detected by esterase starch gel electrophoresis technique.

RESULTSThe PCR-RFLP assay of esterase allele genes for three consecutive years disclosed four esterase genotypes, namely, the world-wide highly active homozygous Est beta 1(1) (50%-54%), homozygous Est beta 2 (29%-34%), heterozygous Est beta 1(1)/beta 2 (5%-10%) and Est beta N (3.13%) of a new homozygous genotype. The research of the resistance associated esterase genes phenotype in natural population of Culex pipiens complex in Hangzhou in 2005 with esterase starch gel electrophoresis technique revealed four major types, namely, Est beta 1(1) (61%), Est alpha 2/beta 2 (12%), Est alpha 8/beta 8 (7%) and sensitive phenotype (29%).

CONCLUSIONThere should be various resistance associated esterase genotypes in natural population of Culex pipiens complex in Hangzhou. During the period of 2003-2005, Est beta 1(1) was the major type; Est alpha 2/beta 2 was the second. Est beta N was a new esterase genotype detected in 2005 only with a mere percentage of 3.13%. As for its resistance to the new insecticide, a follow-up study should be needed. The molecular typing of the amplified esterase gene should be consistent with the resistance associated esterase genes phenotype.

Alleles ; Animals ; China ; Culex ; genetics ; physiology ; Esterases ; analysis ; genetics ; Gene Frequency ; Genotype ; Insecticide Resistance ; genetics ; Phenotype

OBJECTIVETo transfer the effective elements of Bupleurum scorzonerifolium into carrot, and provide theoretical data for the exploitation, improvement and selection of the germplasm of Chinese medicinal plants.

METHODThe protoplasta of Bupleurum scorzonerifolium irradiated by ultraviolet light (UV) at an intensity of 300 microW.(cm2)-1 for 0, 1, 2 min respectively were fused with those of carrot Fisch by PEG method. The regenerated clones, derived form a single fused cell, were examined for their hybrid nature by phenotype and Esterase isoenzyme analysis.

RESULTNine clones were identified as the somatic hybrids between B. scorzonerifolium and carrot.

CONCLUSIONThis provides a firm foundation for the further analysis of the main active components saikosaponin of somatic hybrids and the screening out of high-medicine-content hybrid cell lines.

Bupleurum ; cytology ; genetics ; growth & development ; Cell Fusion ; Culture Techniques ; Daucus carota ; cytology ; genetics ; growth & development ; Esterases ; analysis ; Hybrid Cells ; enzymology ; Hybridization, Genetic ; Isoenzymes ; analysis ; Plants, Medicinal ; cytology ; genetics ; growth & development ; Protoplasts ; cytology

The study was carried out to investigate the genetic polymorphism of the serum proteins of horses in Cheju. They were assigned to three groups; 45 Cheju native horses(CNH), 60 Cheju racing horses(CRH) and 60 Thoroughbreds(TB). We analyzed the phenotypes and gene frequencies of serum proteins which were albumin (Alb), vitamin-D binding protein(GC), esterase (ES), A1B glycoprotein(A1B) and transferrin(TF) loci using horizontal polyacrylamide gel electrophoresis (HPAGE).All of the loci, except A1B in TB, showed polymorphisms and different allelic and phenotypic frequencies in all three groups. ESS and TFF1 were not observed in CNH. Allelic frequencies of AlbB, ESI, TFD and TFF1 were high in TB. All of the loci, except ES locus in CRH, appeared to be in a state of Hardy-Weinberg equilibrium from goodness-of-fit test in all three groups Heterozygosity estimates at Alb, ES and TF loci were high, but GC and A1B loci were low in all three groups. Average heterozygosities in CNH, CRH and TB were 0.3535, 0.3555 and 0.2726, respectively. Results showed differences in the frequencies of alleles and phenotypes of several serum protein loci between CNH and CRH, suggested that CRH might be crossed with other breeds of horses in some degree.
Alleles ; Animals ; Blood Proteins/*genetics ; Electrophoresis, Polyacrylamide Gel ; Esterases/genetics ; Genetic Variation ; Horses/blood/*genetics ; Polymorphism, Genetic ; Serum Albumin/genetics ; Transferrin/genetics ; Vitamin D-Binding Protein/genetics

OBJECTIVE: To research the value of polymorphism of salivary esterase(Set) in paternity and personal identification. METHODS: Phenotype and genotype of human salivary esterase were detected in 114 liquid saliva samples from the Chinese population by disc electrophoresis and fast blue RR staining assay. RESULTS: The frequency of Set type was F 22.81%, FS 50.88%, S2 6.31%. The estimated gene frequency of SetF was 0.4825 and SetS was 0.5175. The PE was 0.1875 and the DP was 0.6199. CONCLUSION Polymorphism of salivary esterase (Set) was practical in paternity and personal identification.
Esterases/genetics* ; Forensic Anthropology/methods* ; Gene Frequency ; Humans ; Paternity ; Polymorphism, Genetic ; Saliva/enzymology*