Human serum albumin

About: Human serum albumin is a research topic. Over the lifetime, 9402 publications have been published within this topic receiving 269029 citations. The topic is also known as: serum albumin & ALB.

Probing the binding affinity of plasma proteins adsorbed on Au nanoparticles

Abstract: Nanoparticle (NP) surfaces are modified immediately by the adsorption of proteins when exposed to human blood, leading to the formation of a protein corona. The adsorption of serum proteins is the key process for exploring the bioapplication and biosafety of NPs. In this study, NP–protein binding affinity (Ka) was investigated. Some serum proteins, such as human serum albumin (HSA), trypsin (TRP), hemoglobin (Hb), myoglobin (MB), immunoglobulin G (IgG), carbonic anhydrase (CA), fibrinogen (FIB), chymotrypsin and r-globulin, were used with gold nanoparticles (AuNPs) to address binding affinity according to isothermal titration calorimetry (ITC) combined with dynamic light scattering (DLS) and fluorescence quenching. The NP protein binding affinities determined by the two methods were in agreement, and depended on the protein properties and size of the NPs. The two methods are convenient, and the results are highly comparable. These methods can be extended to determine the binding affinity of NP protein interactions. The adsorption of proteins upon the AuNP surface is a complex process and depends on several factors, but the binding affinities are higher for proteins with more cysteine residues located on the surface.

FT-IR Analysis for Structural Characterization of Albumin Adsorbed on the Reversed-Phase Support RP-C6:

Abstract: The aim of this study is to demonstrate the reliability of the use of FT-IR spectroscopy to monitor conformational changes when a protein (HSA) is adsorbed under chromatographic conditions on the silica material RP-C6. In the aqueous eluent (D2O), the amount of protein retained on the phase is minimal for 30% CH3CN, whereas no protein is retained for 40%. Structural results are deduced from quantitative analyses of the infrared Amide I' absorptions and from measurements of the peptide NH-ND exchange. Both are performed for HSA in solution and for HSA adsorbed on RP-C6 in suspension in equivalent eluents. For the solutions, 30% CH3CN in the solvent weakly unfolds some structured loops of the protein. Hydration and aggregation are enhanced in 40% CH3CN, which significantly denatures α- and β-domains. When the protein is adsorbed with 0-30% CH3CN in the solvent, about one-tenth of HSA backbone unfolds. In the adsorbed state, the protein is more hydrated and self-associated than in the corresponding solutions. The larger contacts between HSA and RP-C6 are observed when the retention amount is the weakest (30% CH3CN). Results show that retention should have a hydrophobic origin. The irreversibility of the retention is supposed to be dependent on the protein structural and solvation changes observed from the solutions to the adsorbed states. To explain the elution with organic solvent > ~38%, a competition between acetonitrile and the solid phase in solvating hydrophobic domains of the protein is suggested.

Characteristics of bovine hemoglobin as a potential source of hemoglobin-vesicles for an artificial oxygen carrier

Abstract: Hemoglobin-vesicles (HbV) have been developed for use as artificial O(2) carriers in which a purified Hb solution is encapsulated within a phospholipid bilayer membrane. In this study, bovine Hb (BHb) was tested as a source of HbV instead of human Hb (HHb). We compared the preparation process and characteristics of BHbV with those of HHbV. The purification of BHb was effectively performed simply with an ultrafiltration system including a process for removing virus and scrapie reagent. The removal ratio of the phospholipid components of bovine red blood cells was over 99.99%, and the protein purity was over 99.9%. The deoxygenated and carbonylated BHb showed denaturation transition temperatures at 83 and 87 degrees C, respectively, which are higher than those of HHb (80 and 78 degrees C, respectively), and resistant to pasteurization (60 degrees C, 10 h). The purified BHb was concentrated to over 40 g/dl, and encapsulated in a phospholipid bilayer membrane to form BHbV with a diameter of about 280 nm. The O(2) affinity (P(50)) of the BHbV was regulated by coencapsulation of an appropriate amount of Cl(-) (as NaCl), which binds to BHb as an allosteric effector, in the range 16-28 Torr, comparable to human blood (P(50) = 28 Torr). This is quite simple in comparison with HHb which requires phosphate derivatives such as pyridoxal 5'-phosphate as a replacement for 2,3-diphoshoglyceric acid. The viscosity and colloid osmotic pressure of the BHbV when suspended in 5% human serum albumin are 3.5 cP and 20 Torr, respectively, comparable to those of human blood. In conclusion, BHb can be used as a source for the production of HbV, not only because of its abundance in the cattle industry, but also because of the physicochemical advantages of the purification process, thermal stability, and regulation of O(2) affinity in comparison with HHb.