Cationized albumin plasma

AUC, area under curve of plasma concentration Av, avidin NLA, neutral avidin SA, streptavidin cHSA, cationized human serum albumin HIR MAb, human insulin receptor mAb PS product, permeability surface area product. 

Bovine serum albumin has a molecular weight of about 6.6 X 10" and consists of 581 amino acids. The tertiary structure of the protein is controlled by the 17 disulfide linkages, and at pH 7.0 the net charge on the protein is 18. The human plasma protein, ai-acid glycoprotein, contains five carbohydrate units and has a molecular weight of 4.1 x 10". The 14 sialic acid residues in the sugar units are involved in binding various cationic species and are believed to play a role in the chiral selectivity of this protein. 

The main proteins present in blood plasma are albumin (Alb, M 70 kDa, c 600 xm) and transferrin (Tf, M 80 kDa, c 35 xm). Apo-Tf is a bilobal single-chain protein and efficient transporter for Ee + and other tri- and divalent cations, including V + and VO +. Anions, e.g. [H2V04], are also taken up, but possibly reconstructed and bound in the form of VOj. A maximum of two metal ions can be coordinated, one in each binding site... 

From the available data, it appears that cholephilic dyes must be water soluble and noncolloidal. Anionic dyes, regardless of their chemical structure, are excreted by the liver more readily than cationic dyes (H19). Many dyes are bound to plasma albumin, and it has been suggested that those which are more strongly bound are secreted by the liver whereas those which are more loosely bound are excreted by the kidney (B17). Thus, at a concentration in plasma of 1 mg/100 ml, about 20% of phenol red is not protein bound whereas less than 1% of BSP is dialyzable. 

Plasma proteins are amphoteric molecules having both positive and negative charges that contribute to the balance of plasma ions and osmolality, particularly albumin. In cardiotoxicity, plasma protein patterns may be altered with increases of total protein, albumin, and acute phase proteins (e.g., myoglobin, C-reactive protein, and hbrinogen see Chapters 7 and 8). When proteins bind xenobiotics (or metabolites), their contributions to cation/anion balance may be altered. 

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