Molecular signatures of Calpain 10 isoforms sequences, envisage functional similarity and therapeutic potential

Calpain 10 plays a role in insulin secretion, action and susceptibility to type 2 diabetes. The mechanism through which it influences the insulin secretion and action is not completely defined. A structural bioinformatics approach is applied to envision its mechanism of action using available tools on NCBI (blastp and blastn), EMBL-EBI, Ensembl, Swiss Model Repository websites, I-TASSER, PROCHECK program and Discovery Studio software. Homology of domain I and II of calpain10 (isoform a) was established with super family cysteine proteinase domains (II a and II b, e=1.30e-77, 1.00e-20). Remaining sequences of domain III and T from (isoform a and c) indicated some similarity (Avg. e=1.94e-37) to calpain large subunit domain III (PF01067), the isoform g (139 AA) showed similarity with a part of catalytic domain of cysteine protease super family (e-value 1.00e-20). Swiss-model repository for 3D structures of protein, showed structural resemblance of 29% with 1QXP template of mu-calpain, 27% with 1KFX of m-calpain and 32% with 2P0R of calpain 9 in complex with leupeptin. Models prepared through I-TASSER confirmed through Ramachandran (RC) plots. The calpain 10 isoforms a, c and g show partial structural and functional resemblance to m, mu and calpain 9. This information is useful to find new drugs for disease management

Identification of Calpain 10 Isoforms (b, d, e, f & h) Conserved Regions and Possible Functional Prophecy through Bioinformatics

Calpain 10 is an atypical calpain ubiquitously exist in all human tissues. It exhibits eight protein isoforms designated as “a-h” which play a vital role in glucose homeostasis but actual mechanism of action is yet to be ascertained. We have predicted the partial roles of Isoform a, c and g previously. They were envisaged to act partially as mu and m-calpain cysteine proteases. Here we predict the function of minor isoforms b, d, e, f and h. We have applied NCBI Blast and Conserved domain tool for nucleotide and protein alignments. Blast query indicated 87%, 84%, 87%, 94% and 34% identity of isoform b, d, e, f and h with canonical sequence of calpain 10 a isoform. Conserved domain analyses of protein sequences revealed significant structural similarities of their N-terminal domain I and II with catalytic domain of cysteine protease superfamily PC1 (e-value:CAPN10b, d, e = 2.41e-76, CAPN10f = 1.07e-43 and CAPN10h = 1.13e-17). Isoform b, d and e have one consecutive domain similar with C2 like subdomain III (e-value=2.92-32, 1.03e-35, 1.88e-14 respectively) and was classified in CAPN10 group of Palb subfamily. Isoform f and h were lacking this domain and had shorter sequences. Although structural similarities are not guaranteed for similar actions but domain homology predicted the existence of similar functions as of calpain I and II

Tracking down immune markers from alternative system pathway factors in a diabetic population.

Hyperglycemia associated with type 1 diabetes (T1D) alters the host immune system, resulting in a predisposition to infectious diseases. The high risk of infection in the diabetic population may lead to life-threatening situations. The early proteins of the alternative complement system pathway, constituting factors P, B, and D, have been shown to play an important role in preventing infection because they form a membrane attack complex (MAC)-C5-9, which debilitates the target microbes and/or molecules via cytotoxic and cytolytic reactions. Patients who are devoid of or contain low levels of these proteins may be susceptible to developing chronic infections. We have observed striking differences in partially fractionated serum proteins in diabetic Patients (type 2) relative to controls, through single and two-dimensional gel electrophoresis. Our data, obtained from 50 diabetic Patients in the age group of 25-45 years, who had the disease for fewer than 5 years, indicated patterns in low- and high-molecular-weight proteins, which could be grouped into five different categories with minor differences in their respective levels of protein expression. Immunoblot assay could barely detect the presence of properdin expression in diabetic Patients. Quantization by ELISA in 99 Patients indicated low levels of properdin expression in 70% of 50 diabetic Patients (6.5 +/- 3 mug/mL) when compared to nondiabetic controls (19.5 +/- 8.5 mug/mL). This study concluded that Patients with low expression of properdin should be advised to take extensive preventive measures and seek early management with appropriate treatments against infection