title: Binding of cationic porphyrin to human serum albumin studied using comprehensive spectroscopic methods.
abstract: The interaction between cationic porphyrin, a potential valuable anti-tumor and antibiotic drug, and human serum albumin (HSA) was investigated using spectroscopy methods. The binding constants were obtained using fluorescence quenching method (K(SV) = (3.24 +/- 0.29) x 10(4) M(-1)) and surface plasmon resonance (SPR) spectroscopy (K(A) = (6.287 +/- 0.407) x 10(4) M(-1)). The association rate constant (k(a) = 1622 +/- 72.9 M(-1) s(-1)) and dissociation rate constant (K(d) = 0.02589 +/- 0.0024 s(-1)) of the binding process were also calculated. Compared with the two results, it was known that one of the binding sites was near the tryptophan residue and also there existed other binding sites. The Fourier transform infrared (FT-IR) spectroscopy and circular dichroism (CD) spectroscopy indicated that the confirmation of HSA was nearly not affected with the addition of porphyrin.
authors.affiliation: State Key Laboratory of Virology, Department of Chemistry, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhou
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zhang
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ran
authors.initials: R
authors.lastname: Li
authors.forename: Qi
authors.initials: Q
authors.lastname: Xiao
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.forename: Zaoying
authors.initials: Z
authors.lastname: Li
mesh_terms: D002412:Cations / Q000032:analysis / Q000378:metabolism; D002942:Circular Dichroism; D006801:Humans; D011166:Porphyrins / Q000378:metabolism* / Q000502:physiology; D011485:Protein Binding / Q000502:physiology; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D012709:Serum Albumin / Q000032:analysis / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared; D020349:Surface Plasmon Resonance
chemical_list: D002412:Cations; D011166:Porphyrins; D012709:Serum Albumin