Influence of temperature on the binding of sodium aurothiosulphate to human serum albumin

Pedersen, Susanne Møller

doi:10.1016/0006-2952(86)90468-5

Cited by 4 publications

(1 citation statement)

References 16 publications

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“…Hydrophobic bonding is entropy driven through release of ordered water (Perrin, 1986), and although AS for the binding of SMZ to pig albumin binding was positive, it only made a small contribution to AG. Moreover, Klotz (1973) has pointed out that positive values for AS are not diagnostic of hydrophobic interactions, as the binding of some inorganic anions (Cl-, SCN-) and cations (Cu2+, A u + ) by albumin occurs with a gain in entropy (Klotz, 1973;Pedersen. 1986).…”

Section: Discussionmentioning

confidence: 99%

Binding of sulphamethazine to pig plasma proteins and albumin

Munsey

Grigg

Mccormack

et al. 1996

Vet Pharm & Therapeutics

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The interaction of sulphamethazine (SMZ) with pig plasma proteins and albumin was studied by ultrafiltration and equilibrium dialysis. Binding to pig plasma proteins was monophasic (affinity approximately 9.0 mol/L x 10(3)) and the main binding protein was albumin. At 37 degrees C and pH 7.4, the affinity of SMZ for albumin was about 8.0 mol/L x 10(3) and the number of binding sites was estimated as 1.4. Increasing the temperature from 4 to 45 degrees C resulted in a seven-fold decrease in affinity, and increasing pH from 6.0 to 8.0 enhanced affinity for pig albumin ten-fold. The free energy of binding (-delta G) and enthalpy change (-delta H) were around 5.5 and 5.1 Kcal/mol, respectively. The total entropy change (delta S) was small and positive, around 2 cal/mol/degree K. Studies with the fluorescent probes warfarin and dansylsarcosine, suggest that these bind to separate sites on porcine albumin. SMZ displaced both probes and inhibited the deacetylation of p-nitrophenyl acetate by pig albumin. We conclude that: (1) binding of SMZ to pig plasma proteins and albumin is weak; (2) the interaction with albumin is exothermic and enthalpy driven, and (3) pig albumin, like other mammalian albumins, appears to possess discrete binding sites for warfarin and dansylsarcosine. SMZ interacts with both these loci.

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Section: Discussionmentioning

confidence: 99%

Binding of sulphamethazine to pig plasma proteins and albumin

Munsey

Grigg

Mccormack

et al. 1996

Vet Pharm & Therapeutics

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Determination of human serum albumin using aurothiomalate as electroactive label

2005

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A new electroactive label has been used to monitor immunoassays in the determination of human serum albumin (HSA) using glassy-carbon electrodes as supports for the immunological reactions. The label was a gold(I) complex, sodium aurothiomalate, which was bound to rabbit IgG anti-human serum albumin (anti-HSA-Au). The HSA was adsorbed on the electrode surface and the immunological reaction with gold-labelled anti-HSA was then performed for one hour by non-competitive or competitive procedures. The gold(I) bound to the anti-HSA was electrodeposited in 0.1 mol L-1 HCl at -1.00 V for 5 min then oxidised in 0.1 mol L-1 H2SO4 solution at +1.40 V for 1 min. Silver electrodeposition at -0.14 V for 1 min followed by anodic stripping voltammetry were then performed in aqueous 1.0 mol L-1 NH(3)-2.0x10(-4) mol L-1 AgNO3. For both non-competitive and competitive formats, calibration plots in the ranges 5.0x10(-10) to 1.0x10(-8) mol L-1 and 1.0x10(-10) to 1.0x10(-9) mol L-1 HSA, respectively, with estimated detection limits of 1.5x10(-10) mol L-1 (10 ng mL-1) and 1.0x10(-10) mol L-1 (7 ng mL-1), respectively, were obtained. Levels of HSA in two healthy volunteer urine samples were also evaluated, using both immunoassay formats.

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A mass spectrometric investigation of the binding of gold antiarthritic agents and the metabolite [Au(CN)2]− to human serum albumin

2006

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Electrospray ionisation (ESI) mass spectrometry was used to examine the reactions of the clinically used antiarthritic agent [Au(S2O3)2]3-, and AuPEt3Cl, a derivative of another clinically used agent auranofin, with human serum albumin (HSA) obtained from a human volunteer. Both compounds reacted readily with HSA to form complexes containing one or more covalently attached gold fragments. In the case of AuPEt3Cl, binding was accompanied by the loss of the chloride ligand, while for [Au(S2O3)2]3- the mass spectral data indicated binding of Au(S2O3) groups. Experiments performed using HSA with Cys34 blocked by reaction with iodoacetamide were consistent with reaction of both gold compounds with this amino acid. Separate blocking experiments using diethylpyrocarbonate and AuPEt3Cl also provided evidence for histidine residues acting as lower-affinity binding sites for this gold compound. ESI mass spectra of solutions containing [Au(S2O3)2]3- or [Au(CN)2]-, and HSA, provided evidence for the formation of protein complexes in which intact gold molecules were non-covalently bound. In the case of [Au(S2O3)2]3-, these non-covalent complexes proved to be transitory in nature. However, for [Au(CN)2]- a non-covalent complex containing a single gold molecule bound to HSA was found to be stable, and constituted the main adduct formed in solutions containing low-to-medium Au-to-HSA ratios. Evidence was also obtained for the formation of a covalent adduct in which a single Au(CN) moiety was bonded to Cys34 of the protein. AuPEt3Cl reacted to a much lower extent with HSA that had Cys34 modified by formation of a disulfide bond to added cysteine, than with unmodified HSA. This suggests that the extent of modification of the protein in vivo may have an important influence on the transport and bioavailability of gold antiarthritic drugs.

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Influence of temperature on the binding of sodium aurothiosulphate to human serum albumin

Cited by 4 publications

References 16 publications

Binding of sulphamethazine to pig plasma proteins and albumin

Binding of sulphamethazine to pig plasma proteins and albumin

Determination of human serum albumin using aurothiomalate as electroactive label

A mass spectrometric investigation of the binding of gold antiarthritic agents and the metabolite [Au(CN)2]− to human serum albumin

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