Serum albumin physical properties

Deliconstantinos G. Effect of rat serum albumin-cholesterol on the physical properties of biomembranes. Biochem Int 1987 15 467-474. 

TCs are well documented to bind various metal ions, including alkaline earth metals, Al(ni) and transition metals VO(II), Cr(III), Mn(II), Fe(II/III), Co(II), Ni(II), Cu(II) and Zn(II) . TC can form 2 1 TC-metal complexes with transition metal ions in non-aqueous solution, in which the metal is bound at the 2-amido and 3-enolate chelating sites . TCs are present in plasma mainly in the Ca(II)-bound form or Mg(n)-bound form to a lesser extent, when they are not bound to proteins such as serum albumin. Thus, the bioavailability of TCs should be dependent upon the physical and biochemical properties of their metal complexes instead of their metal-free form. 

Physical Properties of Serum Albumin, Fibrinogen, and Tobacco Mosaic Virus... 

Physical property Serum albumin Fibrinogen Tobacco mosaic virus ... 

Using fluorescence polarization, rotational relaxation time, and sedimentation velocity measurements it could be shown that BSA under certain conditions of succinylation, maleylation, or citraconyla-tion exists in an expanded form, very similar in its physical properties to bovine serum albumin expanded by electrostatic repulsion at pH 2... 

In order to elucidate relationships between surface active and film forming properties of food proteins, it is useful to examine the surface active properties of proteins whose physical and molecular properties are well characterized e.g. -casein, bovine serum albumin (BSA), lysozyme ( ), and -lactoglobulin (b-Lg) (2jL). These represent a range of tertiary structures for soluble proteins. Lysozyme is a rigid and roughly ellipsoidal molecule, whereas the hydrophobic -casein molecule is mostly a random coil structure. The b-Lg molecule consists almost entirely of antiparallel -sheet strands organized into a flattened cone ( ). 

The properties of semidilute mixtures of the protein bovine serum albumin and azopolymers mateh well with the simple idea of a photodestruction of the cross-links. As shown by stress relaxation experiments, the shear modulus (at time zero in Fig. 7.9a) is markedly diminished by exposure to UV, whereas the chain dynamics and relaxation time(s) appear not significantly affected. A decrease by more than a factor of 10 of the modulus indicates clearly the dissociation of most interchain associates (Fig. 7.9b). Nevertheless, the dissociation of the protein-polymer complexes may not occur when the cross-links disappear. As pointed by Leibler and colleagues in the case of interpolymer complexes (Pezron et al., 1988), and by Borrega in the case of protein polymer physical gels (Borrega et al., 1999),... 

Human serum albumin (HSA) is very similar to BSA in physical properties (Foster, 1960) and also in the N-F transition near pH 4 (Clark et al., 1962). Therefore, most of the information discussed in Sections I and II will also pertain to HSA. The amino acid sequence of HSA has recently been established (Behrens et al., 1975 Meloun et al., 1975) and shows that the three-domain feature that prevailed in BSA is also evident in the structure of HSA (Fig. 23). However, there were some differences between the data of the two groups. Sequences reported by Meloun et al (1975) included phenylalanine at position 157, which was deleted in the original sequence of Behrens et al. (1975). However, the latter group (Behrens, private communication, 1977) included a phenylalanine at position 157. Other differences occurred in the assignment of acid/amide states of the acidic amino acids and also in the identity of residues at 16 positions. 

Diethylenetriamine penta-acetic acid (DTPA) may be covalently coupled to proteins to provide hexadentate chelating sites for metal ions. The metal-macromolecule complexes are useful as probes in biological systems, and a variety of metals with useful physical properties can be specifically bound. The potential of the system was demonstrated by the preparation of [ In]DTPA-human serum albumin, which was shown to have an in vivo distribution in mice nearly identical to that of [ I]human serum albumin. 

Some of the physical and chemical properties of tetanus, botulinus, and diphtheria toxins, together with comparable data for crystalline human serum albumin, are summarized in Table II. 

Normal individuals excrete 31 mg of albumin in their urine daily. The studies of the physical and chemical properties of the urinary albumin have established that the urinary protein is identical to the blood protein. Both serum and urinary albumin have the same mobilities on free-starch electrophoresis and im-muno-electrophoresis. The sedimentation constants and the diffusion rates of the two proteins are similar, and their molecular weight must be of the order of 73,000. The two proteins react identically antigeni-cally. 

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