6533b855fe1ef96bd12b1adc

RESEARCH PRODUCT

Study of a medium-size biological molecular association by means of a pair potential semiempirical approach: β-carboline-lumiflavin

subject

description

The molecular association between some substituted β-carbolines and a model flavin, lumiflavin, has been studied by means of a semiempirical approach proposed by Fraga based on a 1/R expansion of atom-atom pair potentials. Only stacked minima have been considered because of their possible biological interest. The calculations characterize 15 different minimum stacked conformations, most of them occurring in the complexes considered. The structural and energetic effects of 1–Me, 6–OH and 7–OH substituents of β-carboline are discussed. An equilibrium conformation involving geometric overlap between the pteridinic portion of flavin and the indole group of β-carboline is predicted to be the most characteristic structure of the complexes. The recognition of this feature can serve to check the effect of substituents and substitution sites of β-carboline in its association complexes.