Cross-reacting material

Sixteen patients had an associated hyperammonemia, citrullinemia and hyperlysinemia. This presentation is the most malignant, with death in early infancy. This French phenotype is commonly associated with the absence of any immunological cross-reacting material (CRM) corresponding to the pyruvate carboxylase apoenzyme protein. 

Cross-reactivity The amount of a similar substance that will cause the same displacement of labelled antigen from the antibody as an arbitrary amount of the antigen. The usual definition is ID50, which is the concentration of cross-reacting material required to displace 50% of labelled hapten from the antibody. 

The liver (Cu,Zn)-SOD of old rats (27 months) showed a 60% reduction of specific activity, the presence of antigenically cross-reacting material, and a decreased thermal stability in comparison with the enzyme of young rats (6 months) . Similar observations were made with ageing human fibroblasts in culture, whereby the absence of a cytosolic stabilizing factor was suspected in old cells... 

Two r- subclones of WEHI-7 have been characterized in detail [51,60], One of them displayed a parallel decrease in receptor activity, cross-reacting material, and receptor message. In the other r clone no hormone-binding activity or immuno-reactive material were detected but the cells still expressed a low level of receptor mRNA. Thus multiple controls of receptor expression may be in effect. 

McNeela, E. A., O Connor, D., Gill, J. I., Ilium, L., Davis, S. S., Pizza, M., Peppoloni, S., Rappuoli, R., and Mills, G. H. K. ( 2000), A mucosal vaccine against diphtheria Formulation of cross reacting material (CRM197) of diphtheria toxin with chitosan enhances local and systemic antibodies and Th2 responses following nasal delivery, Vaccine., 19, 1188-1198. 

Mutants constitutive for IP synthase activity were identified on the basis of a phenotype associated with overproduction of mositol (Opi- phenotype) and the subsequent excretion of inositol which can be detected in a bioassay (Greenberg et al., 1982b). Mutants at the OPI1 locus were shown to overexpress IP synthase activity and cross-reacting material, regardless of the presence of exogenous... 

Figure 8-27. Cross-reacting material (bars) and thiogalactoside transacetylase activity (filled circles) in extracts of nonsense mutants. A genetic map of the lac Z gene, indicating the locations of some of the mutations used in this experiment, is shown below. [From A. V. Fowler and I. Zabin, J. Mol. Biol., 33 35 (1968).]...

Researchers have questioned whether the one-enzyme-deficiency theory applies to scurvy-prone animals (13). Studies showed no evidence for more than a one enzyme defect in scurvy-prone animals (14). Based on immunologic evidence of purified L-gulono-A-lactone oxidase, scurvy-prone animals do not contain immunologically cross-reacting material to gulono-A-lactone oxidase (15,16). 

Cross-reactivity is evaluated by comparing the ability of each potential cross-reacting material to displace label. The percent cross-reactivity is equal to 100 times the concentration of analyte at 50% response divided by the concentration of interferent at 50% response. 

The presence of cross-reacting material to antiserum prepared against normal NADP-GDH (189). 

Table 3. Evaluation of cross-reacting materials in Scrophulariaceae leaf crude extracts using anti-digoxin monocional antibody (DIG 64.2B.5).

Despite the fact that all the patients erythrocytes contained the same amount of cross-reacting material, there was evidence of heterogeneity. The neutralization curves of the lysate of erythrocytes of Lesch-Nyhan patients were different even though the amount of serum that completely neutralized antibody was the same (B6). Thus, various immunological as well as genetic and stability data suggest that there are a number of mutations that can lead to the absence of functional HPRT and the clinical entity known as Lesch-Nyhan syndrome. 

In contrast to the observation that as cells aged HPRT catalytic capacity decreased but HPRT antigenic activity was constant, in the same cells APRT catalytic and antigenic activity decreased in parallel. This may explain why subjects with decreased APRT catalytic activity have not been shown to have an inactive immunologically cross-reacting material. It may mean that the inactivation of APRT is much more extensive than simple denaturation. 

The quantities of ADA-cross-reacting material (CRM) in the red cell lysates of the parents and a sister of the proposita were found to be more or less proportional to the observed enzymatic activities, which were about half of the normal average (table 1). This might be an indication, that no detectable ADA protein produced by the mutant allele was present in their cells. It should, however, be noted, that red blood cells are not the most suitable material to study the natu re of possibly unstable mutant proteins, since they can not synthesize new protein. 

Recent studies demonstrated the presence of an atypical lipoprotein that im-munologically corresponded to the a-lipoprotein, a so-called cross reacting material... 

Purification of arginase by immunoadsorption Removal of cross-reacting materials from modified B. subtilis a-amylase by immunoadsorption Purification of the enterotoxin from Clostridium perfringens by immunoadsorption Purification of human C3 proactivator by immunoadsorption... 

Removal of cross-reacting materials from modified B. subtilis a-amylase by immunoadsorption... 

The third mutation is characterized by lack of enzyme activity and immuno-logically cross-reacting materials. With sensitive methods, a residual enzyme activity. less than 1 % of normal, can often be demonstrated... 

We have very recently purified both forms of hexosaminidase to homogeneity from human placental tissue (Tallman et aL, 1974b), They have similar molecular weights. In other studies, these isozymes, purified from beef spleen, had almost identical amino acid composition (Verpoorte, 1972). The hexosaminidases also are immunologically related (Carroll and Robinson, 1972 Srivastava and Beutler, 1973). Antibodies prepared to hexosaminidase B were totally adsorbed by A however, specific anti-A antibodies could be prepared by adsorbing anti-A with hexosaminidase B. There was no cross-reacting material in patients with the classic form of Tay-Sachs disease (type I) using this... 

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