Immunochemical reactivities

The predominant contribution of the folded native structure is amply illustrated by the findings that complete reduction of disulfide bonds and 5-carboxymethylation completely alters the immunochemical reactivity of protein antigens, such as ribonuclease, lysozyme, and other antigens.However, reduction of but two of the four disulfide bonds in ribonuclease had a negligible effect on the ability to precipitate with antibody to native ribonuclease. 

Because of differences in immunochemical reactivity of C3 and C3c, reference materials should be completely converted to C3c and stabilized, as is the case for the international reference material CRM 470. ... 

In order to identify the amino acid residues in the antigenic reactive sites, the following three approaches have so far been pursued in BSA (1) studies on the immunochemistry and conformation of chemical derivatives of BSA specifically modified at particular amino acid residues, (2) the isolation of immunochemically reactive fragments liberated by proteolytic digestion of the protein, and (3) studies of the effects of chemical modification of selected amino acid residues on the immunochemistry and conformation of these immunochemically reactive peptides. 

The amount of work on the effect of chemical modification on the immunochemical reactivity of BSA is rather limited, and the role of several amino acid residues on the antigenic reactive site has not yet been established. Notwithstanding, the studies that were accomplished to date will be reviewed. 

The isolation of a large number of immunochemically reactive fragments with a variety of overlaps and representing various parts of the molecule affords a very effective approach to localizing the antigenic... 

The effect of chemical modification on the immunochemical reactivity, data for which ane very limited. 

Isolation of immunochemically reactive peptides. A good deal of progress has resulted from this approach. 

A. Effect of Chemical Modification on Immunochemical Reactivity of Human Serum Albumin... 

Table X. Physicochemical Properties and Immunochemical Reactivity of Modified Human Serum Albumin" ...

Several immunochemically reactive fragments were isolated fi om HSA by chymotryptic hydrolysis (Press and Porter, 1962), by tryptic... 

An immunochemically reactive fragment of molecular weight 21,000-23,(X)0 was isolated in a pure form (Habeeb, 1978a,b) from tryptic hydrolysates of GSA and PSA. The fragment isolated from GSA inhibited the reaction of GSA-anti-GSA by 67% that isolated from PSA inhibited the homologous PSA-anti-PSA by 79% (Table XIV). Immunoadsorbents prepared with these fragments were capable of binding antibody from ho-... 

Serum albumin, the most abundant plasma protein, has been subjected to extensive studies which resulted in a wealth of information on its chemical and physicochemical properties. Only recently has the amino acid sequence of bovine and human serum albumins become known. Prior to the availability of the amino acid sequence, immunochemical studies on BSA or HSA were hampered by the inability to assign an immunochemically reactive fragment within the sequence of the albumin molecule. With the availability of the sequence, it is becoming possible to identify immunochemically reactive fragments of known sequences. Thus fragments 11-193 and 377-571 were isolated from BSA. These fragments were shown to have rather unusual immunochemical properties. Each... 

The extent of decrease in immunochemical reactivity on succinylation of hen egg-white lysozyme, in conjunction with the results of conformational analysis, has indicated that lysine-33, -96, and -116 form part of the antigenic structure. ... 

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