NISCAIR Online Periodicals Repository Collection: IJBB Vol.39(4) [August 2002]

Resolution of a complex ionic mixture of an apparently homogenous protein preparation by preparative electrophoresis

Mon, 29 Jul 2002 22:58:59 GMT

Title: Resolution of a complex ionic mixture of an apparently homogenous protein preparation by preparative electrophoresis

Authors: Dubey, Ashok K

Abstract: Preparations of recombinant envelope glycoprotein E2 of hepatitis C virus (r-HCV E2), found to be homogeneous by N-terminal amino acid sequencing and mass spectrometry, resolved into multiple ionic species (isoforms) when analysed by isoelectric focusing (IEF) gel electrophoresis in the pI range of 3-10. These isoforms possessed pI values in the range or 4.5-8.2. The major isoform with pI value of approximately 7. 1 was separated from the rest of them by employing a method developed on Gradiflow BF 200, a device based on preparative electrophoresis. This isoform was adjudged to be homogenous by IEF and by native polyacrylamide gel electrophoresis (PAGE).

Page(s): 279-283

Immunoaffinity layering enhances the sensitivity of antigen detection on nitrocellulose strips

Mon, 29 Jul 2002 22:58:59 GMT

Title: Immunoaffinity layering enhances the sensitivity of antigen detection on nitrocellulose strips

Authors: Jamil, Hina; Saleemuddin, Mohammed

Abstract: A simple strategy to remarkably increase the sensitivity of detection of antigens applied as dot or western blot on nitrocellulose membrane using human serum albumin as model antigen has been described. This involves subjecting the antigen bearing nitrocellulose strips to multiple incubation cycles with primary antibody and enzyme conjugated secondary antibody prior to staining for enzyme activity. The sensitivity of detection could be increased up to a thousand fold after three incubation cycles. Aggregation of human serum albumin could be detected by the multiple incubation procedure at very low protein concentration after electrophoresis and transfer onto nitrocellulose.

Page(s): 274-278

Synthesis and biochemical evaluation of benzyl propargyl ethers as inhibitors of 5-lipoxygenase

Mon, 29 Jul 2002 22:58:59 GMT

Title: Synthesis and biochemical evaluation of benzyl propargyl ethers as inhibitors of 5-lipoxygenase

Authors: Barhate, N B; Reddy, Madhava C; Reddy, P Srinivas; Wakharkar, R D; Reddanna, P

Abstract: A series of benzyl propargyl ethers were synthesized and tested as inhibitors of 5- lipoxygenase, the key enzyme involved in leukotriene biosynthesis. Among these, optimum activity was displayed by 1-(2-heptynyloxymethyl) benzene 12 (IC₅₀ 1.2 µM). Addition of carboxyl group at the end of the alkyl side chain attached to the acetylenic group abolished the inhibition. Selective reduction of the acetylenic group to cis or trails double bond reduced the inhibitory potential, the cis isomer 24 showing more than 20-fold higher inhibition than the trans isomer 25. Introduction of sulphur in place of oxygen in th e alkyl side chain attached to the (carboxyalkyl) benzyl group also reduced the inhibition. The IC₅₀value of 12, towards rabbit reticulocyte 15-LOX is > 50 fold higher than that of 5-LOX. These results indicate that compound 12 is a specific inhibitor of 5-LOX.

Page(s): 264-273

Pseudomonas cepacia lipase - mediated transesterification reactions of hydrocinnamates

Mon, 29 Jul 2002 22:58:59 GMT

Title: Pseudomonas cepacia lipase - mediated transesterification reactions of hydrocinnamates

Authors: Priya, K; Venugopal, T; Chadha, Anju

Abstract: Use of lipase from Pseudomonas cepacia in transesterifcation reactions of ethyl hydrocinnamate with different alcohols has been examined. Among the alcohols tested, viz., n-butanol, iso-amyl alcohol, benzyl alcohol, n-octanol and 1-phenylethanol, only n-butanol yielded the transesterified product. Among the solvents tested, viz., n-heptane, n-hexane, cyclohexane, toluene, diisopropylether and n-butanol, the initial rate of transesterification proceeded in the order cyclohexane > n-heptane > n-hexane > diisopropylether > n-butanol > toluene. Using hexane as the solvent and a substrate to enzyme ratio of 1 :5, the substrate to alcohol ratio was varied to maximize the yield. n-Butyl hydrocinnamate was obtained in 92% yield in 48 hr by employing a 1:1 (wt/wt) ratio of ethyl hydrocinnamate to lipase and a 1:5 (vol/vol) ratio of ethyl hydrocinnamate to n-butanol in hexane.

Page(s): 259-263