Amino acid sequence albumin

Importantly, the amino-acid sequence of bovine NRP, with the exception of a single substitution of Tyr for Leu at the N-terminal, is contained within the reported sequence for bovine albumin residues 137 to 149 [73]. 

Different authors used RP-HPLC and UV detection to monitor peptide formation during cheese ripening [174-178], providing valuable information about proteolysis. When large hydrophobic peptide need to be separated an lEC represents the best choice [179]. Nevertheless, the identification of these peptides is essential for the complete understanding of the proteolytic process. The peptides eluted from the LC column can be subjected to ESl-MS for molecular weight determination and MS/MS for amino acid sequence determination, which allow rapid peptide identification [172]. HPLC-ESl-MS and MS/MS techniques have been successfully used for peptide mass fingerprint purposes for sequence analysis of purified albumin from Theobroma cacao seeds [180,181]. 

In spite of this heterogeneity, a number of investigators have studied the amino acid composition and the primary sequence of serum albumin (King and Spencer 1970, 1972 Brown et al. 1971 Spencer 1974 Brown 1975, 1977 Peters and Feldhoff 1975 Reed et al. 1980). The total primary amino acid sequence is illustrated in Figure 3.7 and consists of 582 residues with a calculated molecular weight of 66,267... 

Brown, J. R. 1977. Serum albumin Amino-acid sequence. In Albumin Structure, Function, and Uses. V.M. Rosenoer, M. Oratz and M.A. Rothschild (Editors). Pergamon Press, New York. 

King, T. P. and Spencer, E. M. 1972. Amino acid sequences of the amino and carboxyl terminal cyanogen bromide peptides of bovine plasma albumin. Arch. Biochem. Biophys. 153, 627-640. 

About 20% of milk protein is soluble in the aqueous phase of milk. These serum proteins are primarily a mixture of /3-lactoglobulin, a-lactalbumin, bovine serum albumin, and immunoglobulins. Each of these globular proteins has a unique set of characteristics as a result of its amino acid sequence (Swaisgood 1982). As a group, they are more heat sensitive and less calcium sensitive than caseins (Kinsella 1984). Some of these characteristics (Table 11.1) cause large differences in susceptibility to denaturation (de Wit and Klarenbeek 1984). 

Specific domains of proteins (for example, those mentioned in the section Organic Phase ) adsorbed to biomaterial surfaces interact with select cell membrane receptors (Fig. 8) accessibility of adhesive domains (such as specific amino acid sequences) of select adsorbed proteins may either enhance or inhibit subsequent cell (such as osteoblast) attachment (Schakenraad, 1996). Several studies have provided evidence that properties (such as chemistry, charge, and topography) of biomaterial surfaces dictate select interactions (such as type, concentration, and conformation or bioactivity) of plasma proteins (Sinha and Tuan, 1996 Horbett, 1993 Horbett, 1996 Brunette, 1988 Davies, 1988 Luck et al., 1998 Curtis and Wilkinson, 1997). Albumin has been the protein of choice in protein-adsorption investigations because of availability, low cost (compared to other proteins contained in serum), and, most importantly, well-documented conformation or bioactive structure (Horbett, 1993) recently, however, a number of research groups have started to examine protein (such as fibronectin and vitronectin) interactions with material surfaces that are more pertinent to subsequent cell adhesion (Luck et al., 1998 Degasne et al., 1999 Dalton et al., 1995 Lopes et al., 1999). 

Consider first the immunological distances of 6 and 22 for albumin. As explained in Table II, whichever method of assessing probability (1 or 2) is used, these two albumin distances are not statistically significantly different. There is an 11-19% (average, 15%) probability that 6 and 22 could be obtained by chance even if bear albumin were equally distinct in amino acid sequence from the two panda albumins. 

In recent years there has been a flurry of albumin sequence information, and now amino acid sequences have been deduced for several albumins as well as other members of the multigene family (Table I). The... 

Polymorphisms in the sequences of human albumin are quite rare, but are relatively common in cattle, horses, and sheep (Tucker, 1968). To date, the positions of 43 single-site point mutations in HSA have been determined, largely due to the efforts of F. W. Putnam, and these data are presented in Table 111. The majority of the variants have been identified by anomalous electrophoretic migration (Tarnoky, 1980) or, in one case, by the unusually high affinity for thyroxin (Borst et ai, 1983). Therefore, typical commercial preparations of HSA produced from outdated, pooled blood can be considered essentially homogeneous in amino acid sequence. 

II. Ikenaka, T., Studies on the N- and C-terminal amino acid sequence of human serum albumin. J. Am. Chem. Soc. 82, 3180-3183 (1960). 

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