بلال تقی پور

The combination or genetic connection of the antigens with cholera toxin B (ctB) subunit creates a strong mucosal antibody response. The aim of this study was to connect ctB to protein in domain 4 encoding gene of Protein arginine Domainases (PaD4) to express chimeric protein as a candidate vaccine against anthrax. In this experimental study، polymerase chain reaction (PCR) using specific primers for genes ctB and PaD4 was performed and amplified genes were cloned separately in PGEM-T easy vector. Then، PaD4 gene was connected to the 3'' end of ctB by the enzymatic digestion method and then، ctB-PaD4 fusion genes were sub-cloned into the pET28a. The strain BL21 of E. coli bacteria was transformed by the recombinant vector. The expressed chimeric protein was induced by Isopropyl β-D-1-thiogalactopyranoside and evaluated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot techniques. CtB-PaD4 fusion gene was constructed، confirmed by PCR techniques، and sequencing. This gene was expressed in the E. coli bacteria of strain BL21 at optimum temperature of 37°C، and the chimeric protein was produced successfully. The bond in this protein was confirmed by Western blot technique and SDS. PAGE. After immunogenicity assay، this recombinant protein can be used as a new and effective chimeric subunit vaccine against Bacillus anthraces for oral or nasal consumption in future studies.

Transgenic plastids offer unique advantages in plant biotechnology، including high-level foreign protein expression and posing lower environmental ricks. As regard to sequencing of lettuce plastid genome، many Homologous segments can be used for vector designing to production recombinant proteins in this plant. We have described the development of a plastid transformation system for lettuce، (Lactuca sativa L. TN-96-39-B). The transforming DNA carries a betaine aldehyde -resistance gene BADH cassette (lettuce rrn promoter-BADH- lettuce psbA terminator) under control of lettuce chloroplast regulatory expression elements، flanked by two adjacent lettuce plastid genome sequences allowing its targeted insertion between the rbcL and accD genes. This system will open up new possibilities for the efficient production of plasma proteins، enzymes، growth factors، recombinant edible vaccines and antibodies in lettuce.

From the beginning of DNA structure understanding by Watson & Crick up to now، lots of discoveries have been achieved about the structure of molecules responsible for genetic inheritance. Modern sciences such as genomics and proteomics broadly employ basic cellular and molecular knowledge. Once، based on central dogma، protein synthesis was just explained by template DNA sequence، mRNA and protein molecules with the whole pathway done using triplet codes. But in recent years، a new window of involved processes in protein synthesis has opened including some elements involved in correct binding of each amino acid to appropriate tRNA molecules which guarantee the accuracy of protein sequence synthesis of organisms. Generally، these factors are defined as the secondary genetic codes or identity sets. The latest word on these factors is “supercodes”. These elements include a wide range from tRNA molecules structures to error correction mechanisms.