http://192.168.1.40:8080/xmlui/handle/123456789/1135 Sun, 31 May 2026 15:24:05 GMT 2026-05-31T15:24:05Z http://192.168.1.40:80/xmlui/bitstream/id/ac1e2a8f-983a-45aa-b67b-60f7abbe7dbc/SD1.jpg http://192.168.1.40:8080/xmlui/handle/123456789/1135 http://192.168.1.40:8080/xmlui/handle/123456789/2450 Purification, substrate specificity, and N-terminal amino acid sequence analysis of a beta-lactamase-free penicillin amidase from Alcaligenes sp. Das, Sampa; Gayen, J. R.; Pal, A.; Ghosh, K.; Rosazza, J. P. N.; Samanta, T. B. A β-lactamase-free penicillin amidase from Alcaligenes sp. active against various β-lactams was purified to homogeneity. The enzyme can hydrolyze penicillin G to 6-amino penicillanic acid (6-APA) and furnish penicillin G from 6-APA and phenyl acetic acid by condensation. The penicillin amidase is a heterodimer of subunit masses of 63 kDa and 22 kDa, respectively. Its isoelectric point is at pH 8.5. Cephalothin was found to be the best substrate. This is a novel type II penicillin amidase which shares the properties of both type II and type III enzymes. It is thermostable and, unlike penicillin amidase from A. faecalis, its stability remains unperturbed even in presence of reductant. An inhibition study by 2-hydroxy-5-nitro benzylbromide indicated the involvement of tryptophan in catalysis by the enzyme. DOI: 10.1007/s00253-004-1643-1 Sun, 01 Aug 2004 00:00:00 GMT http://192.168.1.40:8080/xmlui/handle/123456789/2450 2004-08-01T00:00:00Z http://192.168.1.40:8080/xmlui/handle/123456789/1859 Homodimeric Alkaline Phosphatase Located at Helicoverpa armigera Midgut, a Putative Receptor of Cry1Ac Contains alpha-GaINAc in Terminal Glycan Structure as Interactive Epitope Sarkar, Anindya; Hess, Daniel; Mondal, Hossain A.; Banerjee, Santanu; Sharma, Hari C.; Das, Sampa Helicoverpa armigera causes massive yield loss of various crops globally. Bacillus thuringiensis coded Cry1Ac toxin is effective against the pest. Through the present investigation, an alkaline phosphatase type putative receptor of the toxin was identified in the target insect gut BBMV. Lectin-ligand immunoblot assay detected the presence of alpha-GaINAc residue at the nonreducing terminal of the glycan structure in the membrane bound HaALP protein which mediates the toxin-receptor interaction. DOI: 10.1021/pr8006528 Wed, 01 Apr 2009 00:00:00 GMT http://192.168.1.40:8080/xmlui/handle/123456789/1859 2009-04-01T00:00:00Z http://192.168.1.40:8080/xmlui/handle/123456789/1857 Effectiveness of garlic lectin on red spider mite of tea Roy, Anita; Chakraborti, Dipankar; Das, Sampa Red spider mite (Oligonychus coffeae) is one of the major pests of tea and damages 5-15% of the total crop every year. Mannose binding 25 kDa lectins (ASAI, Allium sativum bulb agglutinin I and ASAII, A. sativum bulb agglutinin II), purified from bulbs of A. sativum (Garlic), was analyzed through SDS-PAGE and studied for its agglutination property using rabbit erythrocytes. Cross reactivity of the purified lectin was verified through western blot using anti-ASA antibody. ASAI was found to be a dimer built up of two heteromeric subunits whereas the ASAII is a homodimer. The insecticidal activity of the mixture of ASA lectins was tested against red spider mite in an artificial diet. The LC(50) values for red spider mite was determined to be 12.4 +/- 1.918 mu g/ml. This finding opens up a possibility of using the ASA genes against red spider mite through tea transgenic approach. DOI: 10.1080/17429140701754195 Mon, 01 Sep 2008 00:00:00 GMT http://192.168.1.40:8080/xmlui/handle/123456789/1857 2008-09-01T00:00:00Z http://192.168.1.40:8080/xmlui/handle/123456789/1854 Cre/lox system to develop selectable marker free transgenic tobacco plants conferring resistance against sap sucking homopteran insect Chakraborti, Dipankar; Sarkar, Anindya; Mondal, Hossain A.; Schuermann, David; Hohn, Barbara; Sarmah, Bidyut K.; Das, Sampa A binary expression vector was constructed containing the insecticidal gene Allium sativum leaf agglutinin (ASAL), and a selectable nptII marker gene cassette, flanked by lox sites. Similarly, another binary vector was developed with the chimeric cre gene construct. Transformed tobacco plants were generated with these two independent vectors. Each of the T(0) lox plants was crossed with T(0) Cre plants. PCR analyses followed by the sequencing of the target T-DNA part of the hybrid T(1) plants demonstrated the excision of the nptII gene in highly precised manner in certain percentage of the T(1) hybrid lines. The frequency of such marker gene excision was calculated to be 19.2% in the hybrids. Marker free plants were able to express ASAL efficiently and reduce the survivability of Myzus persiceae, the deadly pest of tobacco significantly, compared to the control tobacco plants. Results of PCR and Southern blot analyses of some of the T(2) plants detected the absence of cre as well as nptII genes. Thus, the crossing strategy involving Cre/lox system for the excision of marker genes appears to be very effective and easy to execute. Documentation of such marker excision phenomenon in the transgenic plants expressing the important insecticidal protein for the first time has a great significance from agricultural and biotechnological points of view. DOI: 10.1007/s00299-008-0585-y Wed, 01 Oct 2008 00:00:00 GMT http://192.168.1.40:8080/xmlui/handle/123456789/1854 2008-10-01T00:00:00Z