فریبا قاسم وند

Abstract This study was performed on the base of importance ofphenylalanine dehydrogenase (PheDH) in the outbreak of phenylketonuria (PKU). In order for PKU screening one of the medical applications of enzyme is, identifying and quantifying the exact amount of L-phe in blood serum. The research question was whether the level of protein expression changes after optimization of codon usage in pET-23a and pPR37 expression vectors in E.coli expression system host and the level of expression of the two vectors are different. In this study, experimental approach has been performed. In this study, pdh gene optimized was used belonging to B.sphaericus that was cloned in the two expression vectors. Codon optimization was performed by online Jcat software. PheDH was purified by Ni-NTA chromatography column. The relative molecular mass of PheDH subunit was about 41KDa by SDS-PAGE 10%.The purity and amount of proteins were assessed by SDS-PAGE. The highest rate of expression was observed at 8h after induction inpETpdh/BL21 (DE3)plysS construction. The level of expression of other construction was very low. Applying this method for purification the specific activity of enzyme was 705 U/mg of protein. Our polyhistidine-tag enzyme can be ideally used for the immobilization on a nickel coated microliter plate surface. On the based of this research, it is recommended for large scale enzyme production. According to the comparison between the twogene construction,presumablypETpdh construction is appropriate for production of PeDH enzyme in large-scale.

Schizophrenia is a compli-cated، debilitative mental disorder. Evide-nce is emerging for the association of pol-ymorphisms in PRODH gene and the increased risk of schizophrenia. In the pres-ent research we investigated the relation-nship between this gene and schizophrenia disease by means of a gene polymorphism using PCR-RFLP technique. Blood samples were prepared from 150 persons suffering from acute Schizophrenia and 160 healthy per-sons volunteering for this project. Based on intended SNP، a pair of primers was design-ned by Oligo7 program and the polymerase chain reaction (PCR) was performed on a thermocycler set. Then the PCR product was treated by appropriate restriction enzymes. Finally، the fragments of digested PCR product were electrophoresed on the gel agarose (4%) and migration pattern of resulted components were compared in he-althy and patient subjects، whereby obtain-ing genotypes of different persons in po-lymorphic position. We utilized SPSS 16. 0 program for statistical investigation of the work and studied SNP 1945T>C and its relation with the disease in statistical population. The findings of the research sho-wed a meaningful relation between the occ-urrence of this nucleotide mutation and its frequency in patients. (P=0. 001) Discussion & Final results of this work indicated that PRODH gene can be considered to be a significant candidate in the population under study as a factor influencing the occurrence of Schizoph-renia.