title: Potential toxicity of sulfanilamide antibiotic: binding of sulfamethazine to human serum albumin.
abstract: Antibiotics are widely used in daily life but their abuse has posed a potential threat to human health. The interaction between human serum albumin (HSA) and sulfamethazine (SMZ) was investigated by capillary electrophoresis, fluorescence spectrometry, and circular dichroism. The binding constant and site were determined to be 1.09×10(4) M(-1) and 1.14 at 309.5 K. The thermodynamic determination indicated that the interaction was driven by enthalpy change, where the electrostatic interaction and hydrogen bond were the dominant binding force. The binding distance between SMZ and tryptophan residue of HSA was obtained to be 3.07 nm according to Fǒrster non-radioactive energy transfer theory. The site marker competition revealed that SMZ bound into subdomain IIA of HSA. The binding of SMZ induced the unfolding of the polypeptides of HSA and transferred the secondary conformation of HSA. The equilibrium dialysis showed that only 0.13 mM SMZ decreased vitamin B(2) by 38% transported on the HSA. This work provides a new quantitative evaluation method for antibiotics to cause the protein damage.
authors: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
authors: Jiabin
authors: J
authors: Chen
authors: Xuefei
authors: X
authors: Zhou
authors: Yalei
authors: Y
authors: Zhang
authors: Haiping
authors: H
authors: Gao
mesh_terms: D000890:Anti-Infective Agents / Q000378:metabolism* / Q000633:toxicity; D002942:Circular Dichroism; D019075:Electrophoresis, Capillary; D004785:Environmental Pollutants / Q000633:toxicity*; D015590:Fluorophotometry; D006801:Humans; D011485:Protein Binding; D012709:Serum Albumin / Q000378:metabolism*; D013053:Spectrophotometry; D013418:Sulfamethazine / Q000378:metabolism* / Q000633:toxicity; D013816:Thermodynamics
chemical_list: D000890:Anti-Infective Agents; D004785:Environmental Pollutants; D012709:Serum Albumin; D013418:Sulfamethazine