International Journal of Biotechnology Applications

Number 1, 2009

1-3
PROTEOMICS APPROACH FOR PREDICTION OF IMMUNOGENIC SITE FROM FOOTAND- MOUTH DISEASE VIRUS

Authors: Gomase V.S, Phadnis A. C., Tripathi A.K

Abstract

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Foot-and-mouth disease is caused by FMDV, an Aphthovirus of the viral family Picornaviridae. Peptide fragments of Foot-and-mouth disease virus protein can be used to select nonamers for use in rational vaccine design and to increase the understanding of roles of the immune system in infectious diseases. Analysis shows MHC class II binding peptides of protein from Footand-mouth disease virus are important determinant for protection of host form viral infection. In this assay we predicted the binding affinity of protein having 213 amino acids, which shows nonamers. These peptides are from a set of aligned peptides known to bind to a given MHC molecule as the predictor of MHC-peptide binding. MHCII molecules bind peptides in similar yet different modes and alignments of MHCII-ligands were obtained to be consistent with the binding mode of the peptides to their MHC class, this means the increase in affinity of MHC binding peptides may result in enhancement of immunogenicity of protein nonamers. Binding ability prediction of antigen peptides to major histocompatibility complex (MHC) class I & II molecules is important in vaccine development from Foot-and-mouth disease virus.

5-13
EFFECT OF DIHYDROPYRIMIDINE DERIVATIVES ON KINETIC PARAMETERS OF E.CAROTOVORA L-ASPARAGINASE

Authors: Warangkar S.C., Khobragade C.N., Dawane B.S., Bhosale R.B

Abstract

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Purified L-asparaginase in combination with other anticancer drugs like pyrimidine derivatives is administered usually in the body to treat ALL. In the present study, L-asparaginase was purified from Erwinia carotovora up to 247.6 fold and its catalytic properties were studied in the presence of eight different dihydropyrimidine (DHP) derivatives, out of eight derivatives only two viz 4- (2'-hydroxy phenyl) -6- methyl -2- thioxo)-1 -N - benzilydene - 1, 4 - dihydropyrimidine - 5 -carboxylic acid ethyl ester (P1) and 4 -(2'-hydroxy-5'-chlorophenyl)-5-acetyl-6-methyl-2 pyrimidinone (P2) were found to be activators of L-asparaginase. Their catalytic effect was assayed at optimum pH 8.6 and at temperature 35Â°C in the absence and presence of derivatives P1 and P2 (20-40 Î¼M) at 0.02-0.1 mM concentration of asparagine. It was found that derivatives below the concentration 5 Î¼g/ml have no effect on the activity. Derivative P1 is found to be a strong activator of the asparaginase activity that was reflected by an increase in the Vmax (1.75 fold by P1 and 2.80 fold by P2 respectively) and decrease in the Km (0.91 fold by P1 and 0.81 fold by P2 respectively). The activation of asparaginase is explained by suppressing the cooperativity for the substrate, producing hyperbolic kinetics with Km of 0.080 mM and by 3 fold increase in the Vmax of the enzyme. The activation by derivative P1 and P2 were additive, at optimal or suboptimal concentrations of both activators (up to 30Î¼g/ ml). The DHP derivatives were further analyzed for quantitative SAR study (QSAR) by using PASS, online software to determine their Pa value. Toxicity and drug relevant properties were analyzed by PALLAS software in terms of their molecular weight and log p values. The results showed both the derivatives P1 and P2 are positive modulators of asparaginase activity and may support the development of novel combination therapy for the treatment of Leukemia and solid blood tumors.