Jafar Vatan dost; Shokofeh Hasanabadi
Volume 23, Issue 1 , May and June 2016, , Pages 169-182
Abstract
Nowadays by genetic engineering, recombinant proteins can be produced massively inresponse to demands of industry.Proteins can be expressed in various expression systems and according to the protein type, the expression system can be cell free system, prokaryotic or eukaryotic-based system. For production ...
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Nowadays by genetic engineering, recombinant proteins can be produced massively inresponse to demands of industry.Proteins can be expressed in various expression systems and according to the protein type, the expression system can be cell free system, prokaryotic or eukaryotic-based system. For production of pharmaceutical proteins in most cases post-translational modifications are necessary and mammalian expression systems are the first choice in this regard. However, due to their problems in high production of recombinant proteins, insect expression systems can be an alternative suitable to achieve high expression of many recombinant and complex proteins. In recent year, S2 cell line from Drosophilawas used as the host for the expression of human and non-human recombinant proteins. This system has the advantages such as high cell density and ability to produce folded recombinant proteins with accurate post-translational modifications, especially gamma carboxylation, provides the potential for application in industrial and commercial area.
Jafar Vatandoost; Melika Fasihfar
Volume 21, Issue 6 , January and February 2015, , Pages 977-984
Abstract
Background and purpose : This study was aimed at detecting candidate protein (s) as a substrate for the drosophila gamma-carboxylase enzyme. Pro-peptide form of the candidates can be used for better gama carboxylation of proteins such as human FIX, that require gamma carboxylation for their activity ...
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Background and purpose : This study was aimed at detecting candidate protein (s) as a substrate for the drosophila gamma-carboxylase enzyme. Pro-peptide form of the candidates can be used for better gama carboxylation of proteins such as human FIX, that require gamma carboxylation for their activity .
Material and Methods: In this study nucleotide sequences of all proteins containing Gla region in human, drosophila and cone snail in the gene bank (NCBI) were used. Genomes screening was performed using the Blastn and Blastp programs. Pro-peptide and Gla region positions of all these proteins were determined using the BLAST program. In addition, other programs such as tblastn program (for predicting the presence of the same proteins), ProDom software (for finding candidate proteins containing Gla domain), PROSITE software (for detecting Drosophila proteins with similar pattern), Pfam and SMART programs (to assess the possible Gla region situation in the candidate proteins), were used.
Results: Screening of Drosophila genome data-base was not able to identify any Gla protein in Drosophila in any of fallowing consensus sequences : mammalian Gla domain, mammalian propeptide consensus sequence, mammalian propeptide pattern sequence and cone snail propeptide consensus sequence. However, screening of Drosophila database, using the propeptide sequences of individual Gla proteins in cone snail, has resulted the detection of at least 9 Gla proteins.
Conclusion: The Number and positions of carboxylation in these candidate proteins are similar to vertebrate Gla proteins. These results provide primary data toward selection of appropriate substrate from Drosophila Gamma–carboxylase.
Vahid Koushki; Jafar Vatandost; Seyyed Ali Mortazavi; AliAkbar Jannatabdi; seyyed Abolfazl Hosseini
Volume 20, Issue 5 , March and April 2014, , Pages 726-737
Abstract
Background: Probiotics are beneficial and non-pathogenic microorganisms. Isolation of probiotic bacteria from traditional dairy products can not only lead to the isolation of probiotic bacteria with special characteristics, but it can offer a good approach for the mass production of traditional dairy ...
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Background: Probiotics are beneficial and non-pathogenic microorganisms. Isolation of probiotic bacteria from traditional dairy products can not only lead to the isolation of probiotic bacteria with special characteristics, but it can offer a good approach for the mass production of traditional dairy products containing natural probiotic bacteria.
Materials and Methods: After collection of dairy products samples from different regions of Sabzevar, they were continuously cultured on the specific media of MRS and MRS Broth. Initial identification of isolates was performed by gram stain, motility test, nitrate reduction test, growth at 15 and 45 °C, growth at pH: 9/6 and fermentation capability of 11 different sugars. To identify desired strains more precisely, the 16S rDNA gene was amplified by PCR with specific primers and then sequenced and BLASTed. Acidic and bile salts conditions tolerance tests were performed for the final confirmation of desired strains.
Results: After continuous culture on specific agar media, 16 strains for further analysis were selected. In early identification of isolates by phenotypic methods, 14 strains were positive. To identify these strains more precisely, the 16S rDNA gene was amplified. Following molecular identification and sequencing of 16S rDNA gene, the BLAST sequence similarities were found with Lactobacillus planetarium. In addition, acidic and bile salts conditions tolerance tests showed that these bacteria had the best growth pattern at PH: 4 and they were able to grow in the presence of bile salts.
Conclusion: Biochemical results showed that the most common strains in the tested dairy products are Lactobacillus. These results also confirmed by the molecular tests. Acidic and bile salts conditions tolerance test, as a main characteristic of probiotic bacteria, showed that the strain was able to withstand these conditions.