Adel Ghorani-Azam, Seyed Ahmad Mohajeri, Bamdad Riahi-Zanjani, Sona Sepahi, Samaneh Sepahi
Amylase is an enzyme with broad hydrolysis activities that catalyzes the hydrolysis of starch into glucose and other small molecules such as maltose. It is an enzyme of glycoside family with surface layer homology (SLH) domain. SLH, which is known as cell wall binding domain is essential for binding to peptidoglycan of cell membranes. Since designing and producing enzymes with strong catalytic activity is essential in future food industry, investigating the similarities of amylases of different species can be helpful in protein engineering of these enzymes. Homology alignment of bacterial and human amylase sequences shows that both sequences contain 511 amino acid that are highly conserved with several repeated sequences that seems to be necessary for catalysis activity and structural conformation of the protein. In this study, we aimed to characterize the most critical structural and catalytic domains of amylase using bioinformatics tools. In this study, it was shown that SLH and starch binding domain (SBD) are extremely conserved in both human and bacterial amylase. In addition, it was shown that similar domain with several repeated di- or tri-peptide sequences existed in almost all amylases indicating that these residues may have valuable functional, structural and evolutional information. The results of this study may provide new insights into biological aspects of proteins that have not yet been elucidated.
Abbas Beh-Pajooh, Mahdi Fasihi-Ramandi, Mahmoud Tavallaie
Rheumatoid arthritis (RA) is characterized by movement disability and pain in the joints. This disease makes the body susceptible to other subsequent diseases, making the condition worse. To find out the underlying genetic diversity of this disease at the genomic level in an Iranian population, we carried out an investigation in the VNTR of IL-4 within its third intron. For this goal we isolated the genomic DNA from blood samples of 576Rheumatoid arthritis patients and 546 healthy controls and investigated the presence or absence of specific amplicons via polymerase chain reaction (PCR). The size of each amplicon on a 1.5% agarose gel corresponded to a certain number of tandem repeats which indicated a specific allele. Statistical test of 𝜒2 Fisher’s exact test and odds ratio (OR) was used to analyze the data. The results showed that RA1/RA1 genotype was the dominant genotype in both healthy controls and patients and the heterozygote genotype of RA1/RA2 was observed more in the healthy controls than patients (108 vs 66) with significant difference of P value < 0.005 and odds ratio of 5.582. However two genotypes of RA2/RA2 and RA2/RA3 were exclusively observed in the patients’ samples with P value= 0.023 and odds ratio of 0.988. We concluded that IL-4 VNTR polymorphism might have a strong association with rheumatoid arthritis and might be a high risk factor for development of Rheumatoid arthritis in the investigated Iranian population.