Molecular characteristics, recombinant expression and activity detection of OsGSTL1 from rice

The mRNA of OsGSTL1 was detected in the roots and leaves of rice plants at seedling and tillering stages, and their roots, leaves and panicles at the heading stage. The full-length open reading frame of OsGSTL1 cDNA was 732 bp and encoded a putative polypeptide of 243 amino acids with a calculated molecular mass of 27.30 kDa and a theoretical pI of 5.50. The protein sequences of OsGSTL1 exhibited typical feature of the lambda class GST, which contained the conserved domain "GST_C_Lambda" in C-terminal alpha helical domain and a highly conserved Cys42 in active center. In silico predictions showed that the OsGSTL1 protein was strongly hydrophilic. The phylogenetic analysis revealed OsGSTL1 belonged to monocots subgroup and was closer to IN2-1 of Z. may. The OsGSTL1 gene was cloned into pYTV vector and was introduced into yeast strain PEP4. Western blot analysis showed that the exogenous OsGSTL1 was expressed in the transformed yeast. The GST activity of the crude extracts of yeast showed that the OsGSTL1 transgenic yeast had higher levels of GST activities than the control yeasts. These findings suggested that the OsGSTL1 was a glutathione S-transferase and could play an important role during the growth and development processes in rice.

Impact of GSTM1 and GSTP1 gene polymorphisms on erythrocyte GST activity / 中国药理学通报

Aim The current study was conducted to investigate the effect of GSTP1 codon 105 polymorphism, alone and in combination with GSTM1-deletion polymorphism, on erythrocyte GST activity in 196 Han Chinese. Methods GST activity was measured in healthy Chinese by a spectrophotometric method (n=196;101 males and 95 females; age range 21～81 years; median 43.5 years). GSTM1 polymorphisms were analyzed by a PCR-Multiplex procedure, whereas GSTP1 polymorphism was analyzed by PCR-RFLP. Results The frequency of GSTM1 null genotype was 56.1% and the frequency of I/I, I/V, and V/V genotypes was 60.7%, 35.2% and 4.1%, respectively, in Han Chinese. The mean erythrocyte GST enzyme activity for I/V genotype group(3.53?0.63 U?g -1Hb) was significantly lower than that for I/I genotypes (4.25?1.07 U?g -1Hb, P=0.000), while significantly higher than that for V/V genotypes (2.44?0.67 U?g -1Hb, P=0.004). In GSTM1(-) group, the GST activity of carriers of GSTM1(-)/GSTP1- I/I is significantly higher than that of GSTM1(-)/GSTP1- I/V or-V/V, however, in GSTM1(+) group, there is no difference between different subgroups. There was no significant difference in the mean GST activity among different age groups. Erythrocyte GST activities were significantly higher in females than in males, but not significantly. Conclusion The GST activity measured by CDNB-based assay is probably strongly correlated with the GSTP1 105Val genotype, although other GST enzymes would tend to dilute the GSTP1 genotype effect.