@article { ISI:000297741100014, title = {Purification, crystallization and preliminary X-ray characterization of a haemagglutinin from the seeds of Jatropha curcas}, journal = {Acta Crystallographica Section F-Structural Biology and Crystallization Communications}, volume = {67}, number = {12}, year = {2011}, month = {DEC}, pages = {1534-1536}, publisher = {WILEY-BLACKWELL}, address = {COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA}, abstract = {

The plant Jatropha curcas (Euphorbiaceae) is an important source of biofuel from the inedible oil present in its toxic seeds. The toxicity arises from the presence of curcin, a ribosome-inactivating protein showing haemagglutination activity. In this communication, the purification, crystallization and preliminary X-ray characterization are reported of a small protein isolated from J. curcas seeds with a molecular mass of 10 kDa that agglutinates rabbit erythrocytes. The protein was crystallized using the hanging-drop vapour-diffusion method and also by the microbatch method in 72-well HLA plates, using PEG 8000 as the precipitant in both conditions. X-ray diffraction data collected from the rod-shaped crystals were processed in the orthorhombic space group P212121. The crystals diffracted to 2.8 angstrom resolution at 103 K.

}, keywords = {haemagglutinins, Jatropha curcas}, issn = {1744-3091}, doi = {10.1107/S1744309111038218}, author = {Nair, Divya N. and Suresh, C. G. and Singh, Desh Deepak} } @article { ISI:000291216800020, title = {Purification, crystallization and X-ray characterization of a Kunitz-type trypsin inhibitor protein from the seeds of chickpea (Cicer arietinum)}, journal = {Acta Crystallographica Section F-Structural Biology and Crystallization Communications}, volume = {67}, number = {6}, year = {2011}, month = {JUN}, pages = {714-717}, publisher = {WILEY-BLACKWELL}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

{A Kunitz-type trypsin inhibitor protein (CPTI) purified from chickpea seeds was estimated to have a molecular mass of 18 kDa on SDS-PAGE. The IC50 value of CPTI was determined to be 2.5 mu g against trypsin. The inhibitory activity of CPTI is 114 TIU (trypsin inhibitory units) per milligram of protein, which is high compared with those of other known Kunitz-type trypsin inhibitors from legumes. CPTI crystallized in three different orthorhombic crystal forms: P2(1)2(1)2 form A, P2(1)2(1)2 form B and P2(1)2(1)2(1). The crystals of P2(1)2(1)2 form angstrom, with unit-cell parameters a = 37.2

}, issn = {1744-3091}, doi = {10.1107/S1744309111015338}, author = {Sharma, Urvashi and Suresh, C. G.} } @article { ISI:000300202400005, title = {Purification and characterization of YxeI, a penicillin acylase from Bacillus subtilis}, journal = {International Journal of Biological Macromolecules}, volume = {50}, number = {1}, year = {2012}, month = {JAN}, pages = {25-30}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The paper reports the purification and characterization of the first penicillin acylase from Bacillus subtilis. YxeI, the protein annotated as hypothetical, coded by the gene yxeI in the open reading frame between iol and hut operons in B. subtilis was cloned and expressed in Eshcherichia coli, purified and characterized. The purified protein showed measurable penicillin acylase activity with penicillin V. The enzyme was a homotetramer of 148 kDa. The apparent Km of the enzyme for penicillin V and the synthetic substrate 2-nitro-5-(phenoxyacetamido)-benzoic acid was 40 mM and 0.63 mM, respectively, and the association constants were 8.93 x 10(2) M-1 and 2.51 x 10(5) M-1, respectively. It was inhibited by cephalosporins and conjugated bile salts, substrates of the closely related bile acid hydrolases. It had good sequence homology with other penicillin V acylases and conjugated bile acid hydrolases, members of the Ntn hydrolase family. The N-terminal nucleophile was a cysteine which is revealed by a simple removal of N-formyl-methionine. The activity of the protein was affected by high temperature, acidic pH and the presence of the denaturant guanidine hydrochloride. (C) 2011 Elsevier B.V. All rights reserved.

}, keywords = {Bacillus subtilis, Conjugated bile acid hydrolases, Ntn hydrolase, Penicillin acylase}, issn = {0141-8130}, doi = {10.1016/j.ijbiomac.2011.09.018}, author = {Rathinaswamy, Priya and Gaikwad, Sushama M. and Suresh, C. G. and Prabhune, Asmita and Brannigan, James A. and Dodson, Guy G. and Pundle, Archana V.} } @article { ISI:000359166300001, title = {Penicillin V acylase from pectobacterium atrosepticum exhibits high specific activity and unique kinetics}, journal = {International Journal of Biological Macromolecules}, volume = {79}, year = {2015}, month = {AUG}, pages = {1-7}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Penicillin V acylases (PVAs, E.C.3.5.11) belong to the Ntn hydrolase super family of enzymes that catalyze the deacylation of the side chain from phenoxymethyl penicillin (penicillin V). Penicillin acylases find use in the pharmaceutical industry for the production of semi-synthetic antibiotics. PVAs employ the N-terminal cysteine residue as catalytic nucleophile and are structurally and evolutionarily related to bile salt hydrolases (BSHs). Here, we report the cloning and characterization of a PVA enzyme from the Gram-negative plant pathogen, Pectobacterium atrosepticum (PaPVA). The enzyme was cloned and expressed in Escherichia coli attaining a very high yield (250 mg/l) and a comparatively high specific activity (430 IU/mg). The enzyme showed marginally better pH and thermo-stability over PVAs characterized from Gram-positive bacteria. The enzyme also showed enhanced activity in presence of organic solvents and detergents. The enzyme kinetics turned out to be significantly different from that of previously reported PVAs, displaying positive cooperativity and substrate inhibition. The presence of bile salts had a modulating effect on PaPVA activity. Sequence analysis and characterization reveal the distinctive nature of these enzymes and underscore the need to study PVAs from Gram-negative bacteria. (C) 2015 Elsevier B.V. All rights reserved.

}, keywords = {Cooperative, Enzyme kinetics, Gram-negative, Penicillin V acylase, Substrate inhibition}, issn = {0141-8130}, doi = {10.1016/j.ijbiomac.2015.04.036}, author = {Avinash, Vellore Sunder and Ramasamy, Sureshkumar and Suresh, C. G. and Pundle, Archana} }