Complexation of Zn(II) to a native sequence tripeptide of human serum albumin studied by 13C nuclear magnetic resonance

1980 ◽  
Vol 58 (8) ◽  
pp. 757-766 ◽  
Author(s):  
Helen Lakusta ◽  
Charles M. Deber ◽  
Bibudhendra Sarkar

Serum albumins from several species, which specifically bind and transport several divalent metals in blood, contain an Asp-X-His or Glu-X-His amino acid triad as their NH2-terminal sequence. We have synthesized a tripeptide, Asp-Ala-His-N-methylamide, corresponding to the native sequence of the human serum albumin N-terminus, and examined its interaction with Zn(II) ions in aqueous solution using carbon-13 nmr techniques. Variations in carbon chemical shifts and spin–lattice relaxation times (T1's) as a function of pH and increments of added Zn(II) were used to delineate sites of Zn(II):peptide interactions. Trends in T1 values indicated that local motions of several of the tripeptide carbons were restricted by an induced order accompanying metal binding. Analysis of spectral data suggested that Zn(II) is coordinated to the His imidazole nitrogen atom and the Asp β-carboxylate oxygen atom(s) in each peptide molecule. Similar experiments using a tripeptide analogue, Gly-Gly-His-N-methylamide, demonstrated that in the absence of a side chain carboxylate group, Zn(II) ions will complex the peptide through the His imidazole group and the N-terminal Gly α-amino group. These results support the possibility of a biologically functional role for the Asp-X-His triad as a liganding template for Zn(II)/protein binding.

Soft Matter ◽  
2021 ◽  
Author(s):  
Zhaoyi Wang ◽  
Ningning Zhang ◽  
Jincheng Li ◽  
Jun Lu ◽  
Li Zhao ◽  
...  

Chiral assemblies by combining natural biomolecules with plasmonic nanostructures hold great promise for plasmonic enhanced sensing, imaging, and catalytic applications. Herein, we demonstrate that human serum albumin (HSA) and porcine...


2020 ◽  
Vol 7 (1) ◽  
pp. 191595 ◽  
Author(s):  
Abdulrahman A. Almehizia ◽  
Haitham AlRabiah ◽  
Ahmed H. Bakheit ◽  
Eman S. G. Hassan ◽  
Rashed N. Herqash ◽  
...  

The interactions of novel anti-cancer therapeutic agents with the different plasma and tissue components, specifically serum albumins, have lately gained considerable attention due to the significant influence of such interactions on the pharmacokinetics and/or -dynamics of this important class of therapeutics. Nazartinib (EGF 816; NAZ) is a new anti-cancer candidate proposed as a third-generation epidermal growth factor receptor tyrosine kinase inhibitor that is being developed and clinically tested for the management of non-small cell lung cancer. The current study aimed to characterize the interaction between NAZ and human serum albumin (HSA) using experimental and theoretical approaches. Experimental results of fluorescence quenching of HSA induced by NAZ revealed the development of a statically formed complex between NAZ and HSA. Interpretation of the observed fluorescence data using Stern–Volmer, Lineweaver–Burk and double-log formulae resulted in binding constants for HSA-NAZ complex in the range of (2.34–2.81) × 10 4 M –1 over the studied temperatures. These computed values were further used to elucidate thermodynamic attributes of the interaction, which showed that NAZ spontaneously binds to HSA with a postulated electrostatic force-driven interaction. This was further verified by theoretical examination of the NAZ docking on the HSA surface that revealed an HSA-NAZ complex where NAZ is bound to HSA Sudlow site I driven by hydrogen bonding in addition to electrostatic forces in the form of pi-H bond. The HSA binding pocket for NAZ was shown to encompass ARG 257, ARG 222, LYS 199 and GLU 292 with a total binding energy of −25.59 kJ mol –1 .


1981 ◽  
Vol 199 (3) ◽  
pp. 465-472 ◽  
Author(s):  
E C Metcalf ◽  
B Crow ◽  
P D G Dean

The interaction of the immobilized triazine dye Cibacron Blue 3G-A with rat, rabbit, sheep, goat, bovine and human serum albumins was studied by affinity gel electrophoresis. Dissociation constants were estimated in each instance and showed human serum albumin to have a significantly higher affinity for the dye than did albumin from any other species. Pretreatment of the defatted proteins with bilirubin (3 mol of bilirubin/mol of protein) did not increase the dissociation constants of the serum albumins, whereas pretreatment with palmitate (7 mol of palmitate/mol of protein) increased the dissociation constant in all cases: 3-fold for human serum albumin, 15-fold for other serum albumins. Increasing the bilirubin/albumin ratio (to 7:1) did not affect the dissociation constant of the albumins studied. Decreasing the palmitate/albumin ratio decreased the dissociation constant for human serum albumin, but did not affect those of bovine and rat albumins. Altering the chain length of the presaturating fatty acid dramatically changed the dissociation constant of both human and bovine serum albumins. Butyrate, hexanoate, octanoate and decanoate did not significantly influence the dissociation constants of bovine and human serum albumins for Cibacron Blue, whereas laurate, myristate and palmitate greatly increased the dissociation constant. These data are discussed in relationship to the behaviour of albumins during dye--agarose column chromatography. In Addendum the effect of nucleotide presaturation on the interaction between Bacillus stearothermophilus 6-phosphogluconate dehydrogenase and the immobilized triazine dyes Cibacron Blue 3G-A and Procion Red HE-3B was examined, and the implications for dye--ligand chromatography are discussed.


1985 ◽  
Vol 63 (11) ◽  
pp. 3117-3121 ◽  
Author(s):  
Masaaki Tabata ◽  
Bibudhendra Sarkar

Equilibrium and spectroscopic studies of Cu(II)-transfer of native sequence tripeptide, L-aspartyl-L-alanyl-L-histidine-N-methyl amide (AAHNMA), representing the Cu(II)-transport site of human serum albumin (HSA), and L-histidine (L-His) are reported. The equilibria in the ternary system, M–A–B (M = Cu(II), A = anionic form of AAHNMA, and B = anionic form of L-His) have been investigated by analytical potentiometry in I = 0.2 [(Na+,H+) (Cl−,OH−)] at 25 °C. The ternary system shows the presence of five mixed ligand complexes: MH2AB, MHAB, MAB, MH−1AB, and MH−2AB. The species distribution and their stability constants were evaluated by the mathematical analysis of the potentiometric data. The species were further confirmed by their individual spectra computed from the absorption measurements. At physiological pH, the equilibrium studies reveal the presence of 13% of MH−1AB (λmax = 530 nm.ε = 90 M−1 cm−1) and 3% MAB (λmax = 595 nm, ε = 97 M−1 cm−1). The combined results of equilibrium and spectroscopic studies indicate the mixed ligand complex CuH−1AB formed by deprotonation of peptide nitrogen as an important intermediate in the Cu(II)-transfer reaction. The stability constant of CuH−1AB is compared to those of other tripeptides which were designed to mimic the specific Cu(II)-transport site of human albumin.


2019 ◽  
Vol 44 (4) ◽  
pp. 524-529 ◽  
Author(s):  
Sibel Korunur ◽  
Bilgin Zengin ◽  
Ali Yilmaz

Abstract Background Human serum albumin (HSA) is often selected as a subject of any study because albumin is the most abundant protein in human blood plasma. NMR is recognized as a valuable method to determine the structure of proteins-ligand and protein-drug complexes. Objective – Aim of the study In this study, protein drug interactions were investigated using 5-Fluorouracil anti-cancer drug and human serum albumin protein. Materials and methods In this context 400 MHz NMR spectrometry was used and NMR relaxation rates in drug-albumin complex were investigated with respect to increase albumin concentration and increase in 5-Fluorouracil (5-FU)-albumin solution temperature. Results The results of this study indicated that 5-FU had a weak association with albumin, and it easily dissociated from the protein to which it was attached. Conclusion The obtained results also gave us useful information about molecular dynamics of drug-albumin interactions.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nicole Adam ◽  
Cédric Y. Reitz ◽  
Anna-Lena Ditter ◽  
Petra J. Panak

Abstract The complexation of Cm(III) with the recombinant human serum albumin (rHSA) (characterized by single deletion of residue Asp-1), is studied in dependence of pH and rHSA concentration using time-resolved laser fluorescence spectroscopy (TRLFS). A Cm(III) rHSA species is formed between pH 6.4 and 10.0 with the conditional stability constant being logK = 6.47 at pH = 7.4. Competition titration experiments with Cu(II) and Zn(II) confirm complexation at the N-terminal binding site (NTS) of rHSA and exclude the involvement of the Multi-Metal Binding Site (MBS). Comparison with a previous study on Cm(III) interaction with native albumin, HSA, points out, that residue Asp-1 is involved in Cm(III) binding to HSA but is not crucial for Cm(III) complexation at the NTS. The results are of major importance for a better understanding of fundamental actinide-protein interaction mechanisms which are highly required for the identification and characterization of relevant distribution pathways of incorporated radionuclides.


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