title: Interaction of proteins with aluminum(III)-chlorophosphonazo III by resonance Rayleigh scattering method.
abstract: In weak acid medium, aluminum(III) can react with chlorophosphonazo III [CPA(III), H(8)L] to form a 1:1 coordination anion [Al(OH)(H(4)L)](2-). At the same time, proteins such as bovine serum albumin (BSA), lysozyme (Lyso) and human serum albumin (HSA) existed as large cations with positive charges, which further combined with [Al(OH)(H(4)L)](2-) to form a 1:4 chelate. This resulted in significant enhancement of resonance Rayleigh scattering (RRS), second-order scattering (SOS) and frequency doubling scattering (FDS). In this study, we investigated the interaction between [Al(OH)(H(4)L)](2-) and proteins, optimization of the reaction conditions and the spectral characteristics of RRS, SOS and FDS. The maximum RRS wavelengths of different protein systems were located at 357-370 nm. The maximum SOS and FDS wavelengths were located at 546 and 389 nm, respectively. The scattering intensities (ΔI) of the three methods were proportional to the concentration of the proteins, within certain ranges, and the detection limits of the most sensitive RRS method were 2.6-9.3 ng/mL. Moreover, the chelate reaction mechanism or the reasons for the enhancement of RRS were discussed through absorption spectra, fluorescence spectra and circular dichroism (CD) spectra.
authors.affiliation: Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China; Chongqing Research Academy of Environmental Sciences, Chongqing, 401147, China.
authors.forename: Zhi-Ping
authors.initials: ZP
authors.lastname: Cui
authors.forename: Shao-Pu
authors.initials: SP
authors.lastname: Liu
authors.forename: Zhong-Fang
authors.initials: ZF
authors.lastname: Liu
authors.forename: Hu-Zhi
authors.initials: HZ
authors.lastname: Zheng
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Hu
authors.forename: Jia-Xing
authors.initials: JX
authors.lastname: Xue
authors.forename: Jing
authors.initials: J
authors.lastname: Tian
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry*; D000818:Animals; D002417:Cattle; D002942:Circular Dichroism; D006801:Humans; D009113:Muramidase / Q000737:chemistry* / Q000378:metabolism; D009942:Organometallic Compounds / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000737:chemistry*; D012709:Serum Albumin / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
chemical_list: D017607:Aluminum Compounds; D009942:Organometallic Compounds; D009943:Organophosphorus Compounds; D012709:Serum Albumin; D009113:Muramidase
keywords: [Al(OH)(H4L)]2-; frequency doubling scattering; proteins; resonance Rayleigh scattering; second-order scattering