Proteins diazotized

Table 7 Conjugation of an amino-containing hapten to protein using the diazotization method Materials...

Figure 4.33 Benzidine can be diazotized with sodium nitrite and HC1 for reaction with proteins through their tyrosine, histidine, or lysine side-chain groups.

Figure 19.23 The conjugation of a tyrosine-containing carrier protein and a tyrosine-containing peptide may be done using bis-diazotized tolidine to form diazo crosslinks.

Mix 0.5 ml of the peptide solution with 0.5 ml of the carrier protein solution. Chill on ice. Add 0.4 ml of the fois-diazotized tolidine solution. There should be a color change from orange to red almost immediately. Continue the reaction for 2 hours on ice in the dark. 

Instead of using human serum albumin as a carrier protein, other workers (135) utilized ovalbumin for preparing the diazotized clenbuterol antigen in an enzyme immunoassay developed for screening of clenbuterol residues in bovine urine, liver, and eye. Alkaline phosphatase rather than -galactosidase was also used as an enzyme label in the preparation of the enzyme-clenbuterol conjugate. 

Diazotization of proteins with diazonium-l/f-tetrazole in previous work has been studied in terms of reaction with histidine and tyrosine residues (50, 51). When E. coli pyrophosphatase was incubated with this reagent, there was pseudo-first-order inactivation, but analysis of the... 

Figure 151 Bis-diazotized tolidine can form cross-links with proteins through available tyrosine, histidine, or lysine residues.

Labelling of proteins with 211 At via diazotized 1,4-diaminobenzene and para-aminobenzoic acid... 

All other investigations in this field were directed towards conjugating astatine with proteins. In most cases / -astatobenzoic acid (PAtBA) is produced first via diazotization PAtBA is subsequently bound to the NH2 group of protein by means of acylation with mixed anhydrides42 14. 

Boyd and coworkers583 also labelled lima-bean lectin with 131I (indirectly, by coupling of [131I]-p-iodoaniline to protein by diazotization)584 and visible dyes,584,585 and quantitated the binding to type A erythrocytes. 

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