A Study of the Interaction Between trans-Dehydrocrotonin, a Bioactive Natural 19-nor-Clerodane, and Serum Albumin

Journal of the Brazilian Chemical Society

Soares, Breno A.¹  Maciel, Maria Aparecida M.¹  Universidade Federal do Rio Grande do Norte, Natal, Brazil¹  Universidade Federal Rural do Rio de Janeiro, Seropédica, Brazil¹  Sant'Anna, Carlos Maurício R.¹  Cesarin-Sobrinho, Dari¹  Netto-Ferreira, José Carlos¹  Chaves, Otávio Augusto¹  Ferreira, Aurélio B. B.¹  Instituto Nacional de Metrologia, Qualidade e Tecnologia, Duque de Caxias, Brazil¹ 

关键词:  Croton cajucara Benth.;    bovine serum albumin;    fluorescence;    circular dichroism;    molecular modeling;   

DOI  :  10.5935/0103-5053.20160069

学科分类：化学（综合）

来源: SciELO

【 摘 要 】

The interaction between 19-nor-clerodane trans-dehydrocrotonin (from Croton cajucara Benth.) and bovine serum albumin was studied, applying spectroscopic techniques (fluorescence and circular dichroism), combined with molecular modeling. Fluorescence quenching of albumin by the nor-clerodane (kq ca. 1011 mol L-1 s-1 and Stern-Volmer, KSV, increase with temperature) indicates a combination of static and dynamic quenching mechanism. The binding constant (Kb ca. 103 mol L-1) and circular dichroism data suggest that this association is weak and causes only a moderate change in the α-helix content of the protein. Thermodynamic parameters indicate a spontaneous (Gibbs free energy, ΔGº, ca. -21.28 kJ mol-1 at 310 K) and probably entropy-driven (ΔSº = 0.072 kJ mol-1 K-1) association, typical of hydrophobic interactions. The number of binding sites (n ca. 1) indicates one main binding site and molecular modeling suggests subdomain IIIA (Sudlow's site II) as the main binding site to the nor-clerodane, which is able to make hydrophobic interactions with leucine (Leu)-24, phenylalanine (Phe)-36, valine (Val)-40 and tryptophan (Trp)-134 residues.

【 授权许可】

Unknown