The SRM12/ADA1 Gene Sequence Inserted into Recombinant Plasmids Makes Them More Mitotically Stable in Budding Yeast Cells

TheSRM12/ADA1 gene sequence inserted into a recombinant circular plasmid improves its maintenance in budding yeast (Saccharomyces cerevisiae) cells. Plasmid stabilization caused by the integrated SRM12 sequence does not require the SRM12 function complementing the srm12 mutation and depends on the orientation of the inserted sequence in the vector. This stabilization is mainly due to a decrease in spontaneous plasmid underreplication/copy loss rather than an increase in the fidelity of mitotic plasmid segregation.     

Optimization of expression of hepatitis B surface antigen gene in yeasts

A series of recombinant plasmids has been constructed for expression of the hepatitis B viral surface antigen gene (HBsAg) under the control of the regulatory elements of the yeast acidic phosphatase gene (PHO5). The obtained plasmids possess the high mitotic and structural stability in the transformant yeast cells. The effect of different structural modifications of the vector on the level of HBsAg synthesis in yeasts has been studied. Optimal construction devoid of the bacterial DNA sequences and pre-S region has been selected.     

Intramolecular carboxylate catalysis in the depurination of a 7-methylguanosine derivative

We have compared the pH-independent rates of glycosidic hydrolysis in a carboxylate-bearing 7-methylguanosine derivative with those of a reference compound and with that of 7-methylguanosine itself. A syn-oriented carboxylate group affords catalysis in the hydrolysis reaction, although the instability of 7-alkylguanosines above pH 7 severely limits the useful pH range that could be studied. The effect of the carboxylate near neutral pH can be viewed in three different ways: it provides a 3-fold acceleration as compared to underivatized 7-methylguanosine, an approximately 30-fold acceleration when the decelerating effect of the ketal group is considered, and because of slow decomposition of the reference compound under the reaction conditions, we conclude that the carboxylate provides an acceleration of ≥43-fold as compared to the protio reference compound.     

Digital scanning-integrating cytospectrophotometer]

A principal scheme of the digital scanning and intergrating cytospectrophotometer is described which permits to measure the integrating optical density of specifically stained preparations, "spot" optical density of any absorbing preparations and the area of absorbing objects in two different levels of absorbtion.     

Expression and Purification of Membrane Proteins in Different Hosts

International Journal of Peptide Research and Therapeutics - Membrane proteins play important functions, such as cellular communication and transferring materials in the cell. Many membrane...     

Pierce into the Native Structure of Ata,a Trimeric Autotransporter of Acinetobacter baumannii ATCC 17978

International Journal of Peptide Research and Therapeutics - Acinetobacter baumannii is an important pathogen responsible for nosocomial infections worldwide. Trimeric autotransporters, the...     

Immune response variations to Salmonella enterica serovar Typhi recombinant porin proteins in mice

ObjectivesTyphoid fever is caused by Salmonella enterica serovar Typhi. OmpC, OmpF and OmpA, the three major outer membrane proteins (OMPs), could serve as vaccine candidates.MethodsThe porins antigenicity was predicted in silico. The OMP genes were amplified, cloned and expressed. Sero-reactivities of the recombinant proteins purified by denaturing method were assayed by ELISA. BALB/c mice were immunized with the recombinant porins followed by bacterial challenge.ResultsBacterial challenge of the animal model brought about antibody triggering efficacy of the antigen in OmpF > OmpC > OmpA order. Experimental findings validated the in silico results. None of the antigens had synergic or antagonistic effects on each other from immune system induction points of view. Despite their high immunogenicity, none of the antigens was protective. However, administration of two or three antigens simultaneously resulted in retardation of lethal effect. Porins, in addition to their specific functions, share common functions. Hence, they can compensate for each other's functions.ConclusionsThe produced antibodies could not eliminate the pathogenicity by blockade of one or some of the antigens. Porin antigens are not suitable vaccine candidates alone or in denatured forms. Native forms of the antigens maybe studied for protective immunogenicity.     

Simultaneous impact of atorvastatin and mesenchymal stem cells for glioblastoma multiform suppression in rat glioblastoma multiform model

Glioblastoma multiform (GBM) is known as an aggressive glial neoplasm. Recently incorporation of mesenchymal stem cells with anti-tumor drugs have been used due to lack of immunological responses and their easy accessibility. In this study, we have investigated the anti-proliferative and apoptotic activity of atorvastatin (Ator) in combination of mesenchymal stem cells (MSCs) on GBM cells in vitro and in vivo. The MSCs isolated from rats and characterized for their multi-potency features. The anti-proliferative and migration inhibition of Ator and MSCs were evaluated by MTT and scratch migration assays. The annexin/PI percentage and cell cycle arrest of treated C6 cells were evaluated until 72 h incubation. The animal model was established via injection of C6 cells in the brain of rats and subsequent injection of Ator each 3 days and single injection of MSCs until 12 days. The growth rate, migrational phenotype and cell cycle progression of C6 cells decreased and inhibited by the interplay of different factors in the presence of Ator and MSCs. The effect of Ator and MSCs on animal models displayed a significant reduction in tumor size and weight. Furthermore, histopathology evaluation proved low hypercellularity and mitosis index as well as mild invasive tumor cells for perivascular cuffing without pseudopalisading necrosis and small delicate vessels in Ator?+?MSCs condition. In summary, Ator and MSCs delivery to GBM model provides an effective strategy for targeted therapy of brain tumor.