Spectroscopic Studies on the Molecular Ageing of Serum Albumin

Abstract

Pathological states in the organism, e.g., renal or hepatic diseases, cataract, dysfunction of coronary artery, diabetes mellitus, and also intensive workout, induce the structural modification of proteins called molecular ageing or N-A isomerization. The aim of this study was to analyze the structural changes of serum albumin caused by alkaline ageing using absorption, spectrofluorescence, and circular dichroism spectroscopy. The N-A isomerization generates significant changes in bovine (BSA) and human (HSA) serum albumin subdomains—the greatest changes were observed close to the tryptophanyl (Trp) and tyrosyl (Tyr) residue regions while a smaller change was observed in phenyloalanine (Phe) environment. Moreover, the changes in the polarity of the Trp neighborhood as well as the impact of the ageing process on α-helix, β-sheet content, and albumin molecule rotation degree have been analyzed. Based on the spectrofluorescence study, the alterations in metoprolol binding affinity to the specific sites that increase the toxicity of the drug were investigated.

Differentiation of glycated residue numbers on heat‐induced structural changes of bovine serum albumin

“…One Trp residue (Trp‐134) was located near the surface, but buried in a hydrophobic pocket in domain IB; another (Trp‐213) was located in an internal part of domain IIA . The 20 Tyr residues of BSA are deployed in five subdomains of BSA, with some of them buried in hydrophobic regions . Trp residues are mainly responsible for the intrinsic fluorescence of the protein, because of the very low quantum yield of Phe residues and greatly inter‐quenched Tyr residues .…”

“…47,48 The 20 Tyr residues of BSA are deployed in five subdomains of BSA, with some of them buried in hydrophobic regions. 29,49 Trp residues are mainly responsible for the intrinsic fluorescence of the protein, because of the very low quantum yield of Phe residues and greatly inter-quenched Tyr residues. 32 Synchronous fluorescences at Δ = 15 nm (Syn15) and Δ = 60 nm (Syn60) could be used to measure changes in intrinsic fluorescence of Tyr and Trp residues, respectively.…”

Facile One‐Pot Synthesis of Intrinsically Radiolabeled 64Cu‐Human Serum Albumin Nanocomposite for Cancer Targeting

“…In neutral aqueous solution, the free carboxyl groups in HSA are partly deprotonated to form negatively charged HSA ions. The pure HSA aqueous solution has a characteristic absorption peak at 280 nm (Figure B ) …”

“…The pure HSA aqueous solution has a characteristic absorption peak at 280 nm ( Figure 1B). [12] On adding CuCl 2 solution (in the form of Cu 2 + ions) drop wise to the HSA solution, a pale blue solution was formed due to electrostatic attraction between positively charged Cu 2 + ions and negatively charged HSA, resulting in the formation of a Cu-HSA adduct as evident from the disappearance of the absorption peak at 280 nm ( Figure 1B). This result also indicated that the tertiary structure of HSA was significantly altered on addition of Cu 2 + ions.…”

Interaction study of monoisoamyl dimercaptosuccinic acid with bovine serum albumin using biophysical and molecular docking approaches

“…There are two tryptophan residues in BSA, located in subdomain IIA and IA at positions 212 and 134, respectively. The chemical microenvironment of Trp 212 of BSA is equivalent to Trp 214 in human serum albumin (HSA) 15 , 16 . Herein, we have planned to investigate the mechanistic interactions between BSA and MiADMSA under physiological conditions using different spectroscopic techniques UV–Visible spectroscopy, fluorescence spectroscopy, infrared spectroscopy, and circular dichroism (CD).…”