The Variable Expression of the C 4/5 Complex of Human Butyrylcholinesterase and Body Mass Index

AbstractThe activity of a supposedly heteromeric complex (C4/5) of butyrylcholinesterase (BChE; EC 3.1.1.8) was analyzed in relation to body mass index(BMI). The activities of the C4/5 and COF (other molecular forms) bands in CHE2 C5- (n = 447) and CHE2 C5+ (n = 88) individuals were quantified by densitometry. Since the absolute activity of C4/5 (AC4/5) showed the highest correlation coefficient with weight in the CHE2 C5- phenotype when compared to the other BChE activity variables (total, relative C4/5, and absolute COF), this variable was used for the classification of 51 CHE2 C5- individuals into three groups (low, average, and high), paired by sex, age, and ethnic origin. The low AC4/5 group was found to present a significantly (p < 0.0001) lower mean BMI (22.9) than the other groups (average = 25.2, and high = 26.3). In the CHE2 C5+ individuals no statistically significant standardized regression coefficient was verified between BMI (dependent variable) and the C4/5 band activities. These data show that the behavior of the C4/5 band in relation to BMI differs between the CHE2 C5- and CHE2 C5+ phenotypes. While the C5 band of the CHE2 C5+ individuals is negatively associated with fat storage in the adipose cells, the present data show that the C4/5 band is positively associated with this storage in the CHE2 C5- phenotype.