Study of <i>in Vitro</i>Interaction of Sildenafil Citrate with Bovine Serum Albumin by Fluorescence Spectroscopy

• 作者: Asma Rahman Md. Abdus Salam Md. Rokonujjaman Md. Zakir Sultan Ummay Nasrin Sultana
• 来源期刊: 药理与制药(英文)
• 学科: 化学
• 关键词: SILDENAFIL CITRATE Bovine Serum ALBUMIN Quenching Fluorescence Spectroscopy
• 年，卷（期）: 2015,（2）
• 页码范围: 94-101
• 页数: 8页
• 分类号: O6

摘要

In vitro interaction of sildenafil citrate (SC) with bovine serum albumin (BSA) was investigated at two excitation wavelengths of BSA (280 nm and 293 nm) at two different temperatures (298 K and 308 K) by fluorescence emission spectroscopy. The study showed that quenching of BSA fluores-cence by sildenafil citrate was the result of formation BSA-SC complex with probable involvement of both tryptophan and tyrosine residues of BSA. Fluorescence quenching constant was determined from Stern-Volmer equation, and both static quenching and dynamic quenching were showed for BSA by SC at the conditions. Van’t Hoff equation was used to measure the thermodynamic parameters ΔG, ΔH, and ΔS at the temperatures which indicated that the hydrogen bond and the hydrophobic forces played major roles for BSA-SC complexation. The binding number (n) was found to be ≈1 indicating that one mole BSA bound with one mole SC. The binding affinity of SC to BSA was calculated at different temperatures. The binding constant was decreased with increasing temperatures indicating that stability of BSA-SC complex decreased with increasing temperatures.