Please use this identifier to cite or link to this item: http://nopr.niscair.res.in/handle/123456789/3635
Title: Evidence for the presence of a critical histidine residue at the active site in glyceraldehyde-3-phosphate dehydrogenase of Ehrlich ascites carcinoma cells
Authors: Ghosh, Swapna
Ray, Manju
Ray, Subhankar
Keywords: Glyceraldehyde-3-phosphate dehydrogenase;Ehrlich ascites carcinoma cell;Active site histidine;Diethyl pyrocarbonate (DEPC);Inactivation
Issue Date: Feb-2004
Publisher: CSIR
Abstract: Ehrlich ascites carcinoma (EAC) cell glyceraldehyde-3-phosphate dehydrogenase (GA3PD) (EC. 1.2.1.12) was completely inactivated by diethyl pyrocarbonate (DEPC), a fairly specific reagent for histidine residues in the pH range of 6.0-7.5. The rate of inactivation was dependent on pH and followed pseudo-first order reaction kinetics. The difference spectrum of the inactivated and native enzymes showed an increase in the absorption maximum at 242 nm, indicating the modification of histidine residues. Statistical analysis of the residual enzyme activity and the extent of modification indicated modification of one essential histidine residue to be responsible for loss of the catalytic activity of EAC cell GA3PD. DEPC inactivation was protected by substrates, D-glyceraldehyde-3-phosphate and NAD, indicating the presence of essential histidine residue at the substrate-binding region of the active site. Double inhibition studies also provide evidence for the presence of histidine residue at the active site.
Page(s): 7-13
URI: http://hdl.handle.net/123456789/3635
ISSN: 0301-1208
Appears in Collections:IJBB Vol.41(1) [February 2004]

Files in This Item:
File Description SizeFormat 
IJBB 41(1) 7-13.pdf228.35 kBAdobe PDFView/Open


Items in NOPR are protected by copyright, with all rights reserved, unless otherwise indicated.