Immunoglobulin specific activity

Freedman, D.J., Tacket, C.O., Delehanty, A., Maneval, D.R., Nataro, J., and Crabb, J.H. 1998. Milk immunoglobulin with specific activity against purified colonization factor antigens can protect against oral challenge with enterotoxigenic Escherichia coli. J. Infect. Dis. Ill, 662-667. 

Labeling should be carried out on immunoglobulin preparations derived from the selected antisera, so as to maximize the proportion of specific antibody to total protein and hence reduce non-specific activity in the final reagent. Immunoglobulin can be prepared by any of the methods described above, but only in the most demanding systems will it be necessary to prepare immunospecific antibody rather than a crude immunoglobulin fraction. 

To prepare an iodinated protein with high specific activity, the following example is given for the iodination of immunoglobulin. 

The authors suggested that an unknown mechanism associated with intravenous immunoglobulin infusion had caused non-specific activation of complement systems accompanied by fulminant hypercytokinemia. 

An antibody specific for a transmembrane immunoglobulin -will activate a B cell by cross-linking these receptors. This experiment can be carried out using, for example, a goat antibody to cross-link receptors on a mouse B cell. 

Fig. 4. Enzyme inhibition Effect of an epitope specific antibody. Various amount of C-1-23 antibodies were incubated for 4 hr at 4°C with 500 ng of enzyme and subsequently assayed using standard conditions (6) for 5 min at 30° C in presence of 10 pg of DNA and total histone and 200 pM [ P-]N (30,000 cpm/nmol). The percentage of inhibition is defined as (1 minus the ratio of the activity in the presence absence of antibodies) x 100. The specific activity of the purified enzyme after a 4 hr incubation was 1150 nmol/mg/ min. Gel analysis of the mixture of an enzyme to antibody weight ratio of 1 is shown before (0) and after (4) incubation. E enzyme, Lc light c n and He heavy chain of immunoglobulin.

Demonstration (by immuno-adsorption) of the cell-free synthesis of ribonuclease I-specific immunoglobulin Studies of the conformations of soluble and immobilized enzymes by differential scanning calorimetry and of the thermal stability and specific activity of the immobilized enzyme... 

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