TY - JOUR
T1 - Cigarette smoke induces p-benzoquinone-albumin adduct in blood serum
T2 - Implications on structure and ligand binding properties
AU - Ghosh, Arunava
AU - Choudhury, Aparajita
AU - Das, Archita
AU - Chatterjee, Nabendu S.
AU - Das, Tanusree
AU - Chowdhury, Rukhsana
AU - Panda, Koustubh
AU - Banerjee, Rajat
AU - Chatterjee, Indu B.
N1 - Funding Information:
Funding: This research was supported by CSIR, Government of India , grant no. 37(1368)/09-EMR-II and Juthika Research Foundation of Calcutta University . AG (PhD scholar) is a senior research fellow of CSIR; AC (PhD scholar; AD (PhD scholar) is Juthika Research Fellow; ND (PhD scholar) a CSIR senior research fellow; IBC is INSA Honorary Scientist. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript.
PY - 2012/2/26
Y1 - 2012/2/26
N2 - Earlier we had reported that irrespective of the source cigarette smoke (CS) contains substantial amounts of p-benzosemiquinone, which is readily converted to p-benzoquinone (p-BQ) by disproportionation and oxidation by transition metal containing proteins. Here we show that after CS-exposure, p-BQ-protein adducts are formed in the lungs as well as serum albumin of guinea pigs. We also show that serum of human smokers contains p-BQ-albumin adduct. It is known that human serum albumin (HSA) plays a very important role in binding and transport of a variety of ligands, including fatty acids and drugs. We show in vitro that p-BQ forms covalent adducts with free amino groups of all twenty amino acids as well as e{open}-amino groups of lysine residues of HSA in a concentration dependent manner. When HSA is incubated with p-BQ in the molar ratio of 1:1, the number of p-BQ incorporated is 1. At the molar ratio of 1:60, the number of p-BQ incorporated is 40. The formation of HSA-p-BQ adduct has been demonstrated by absorption spectroscopy, MALDI-MS and MALDI-TOF-TOF-MS analyses. Upon complexation with p-BQ, the secondary structure and conformation of HSA are altered, as evidenced by steady state and time-resolved fluorescence, circular dichroism, 8-anilino-1-napthalenesulfonic acid binding and differential scanning calorimetry. Alteration of the structure and conformation of HSA results in impairment of its ligand binding properties with respect to myristic acid, quercitin and paracetamol. This might be one of the reasons why transport and distribution of lipids and drugs are impaired in smokers.
AB - Earlier we had reported that irrespective of the source cigarette smoke (CS) contains substantial amounts of p-benzosemiquinone, which is readily converted to p-benzoquinone (p-BQ) by disproportionation and oxidation by transition metal containing proteins. Here we show that after CS-exposure, p-BQ-protein adducts are formed in the lungs as well as serum albumin of guinea pigs. We also show that serum of human smokers contains p-BQ-albumin adduct. It is known that human serum albumin (HSA) plays a very important role in binding and transport of a variety of ligands, including fatty acids and drugs. We show in vitro that p-BQ forms covalent adducts with free amino groups of all twenty amino acids as well as e{open}-amino groups of lysine residues of HSA in a concentration dependent manner. When HSA is incubated with p-BQ in the molar ratio of 1:1, the number of p-BQ incorporated is 1. At the molar ratio of 1:60, the number of p-BQ incorporated is 40. The formation of HSA-p-BQ adduct has been demonstrated by absorption spectroscopy, MALDI-MS and MALDI-TOF-TOF-MS analyses. Upon complexation with p-BQ, the secondary structure and conformation of HSA are altered, as evidenced by steady state and time-resolved fluorescence, circular dichroism, 8-anilino-1-napthalenesulfonic acid binding and differential scanning calorimetry. Alteration of the structure and conformation of HSA results in impairment of its ligand binding properties with respect to myristic acid, quercitin and paracetamol. This might be one of the reasons why transport and distribution of lipids and drugs are impaired in smokers.
KW - Cigarette smoke
KW - Fluorescence spectroscopy
KW - Human serum albumin
KW - Ligand binding
KW - MALDI-MS
KW - P-Benzoquinone
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U2 - 10.1016/j.tox.2011.11.014
DO - 10.1016/j.tox.2011.11.014
M3 - Article
C2 - 22154986
AN - SCOPUS:84856089577
SN - 0300-483X
VL - 292
SP - 78
EP - 89
JO - Toxicology
JF - Toxicology
IS - 2-3
ER -