Site-specific conjugation of immunoglobulins and detectable labels
First Claim
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1. A process for producing a derivatized immunoglobulin, said process comprising the steps of:
- (a) site-specifically oxidizing the glycosylated zone of the Fc region of an immunoglobulin with an oxidant to convert at least two hydroxyl groups in said zone of said immunoglobulin to an aldehyde group;
(b) reacting the oxidized immunoglobulin of step (a) with a disulfide compound wherein at least one of said aldehyde groups is reductively aminated to introduce a disulfide moiety onto the Fc region of said immunoglobulin; and
(c) selectively reducing the disulfide bonds of the disulfide moiety of the reacted immunoglobulin of step (b) with an amount of a reductant sufficient to convert at least one of said disulfide moieties of said immunoglobulin into two sulfhydryl groups but insufficient to reduce the disulfide bonds in the complementarity defined region and the hinge region of said immunoglobulin thereby leaving the disulfide bonds in said complementarity defined region and said hinge region essentially unaffected.
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Abstract
A process for producing a derivatized immunoglobulin and conjugates prepared therewith are provided. The derivatized immunoglobulin is produced by introducing sulfhydryl groups in the Fc region of an immunoglobulin wherein the Fab portion of the immunoglobulin is not altered. The derivatized immunoglobulin is used to prepare conjugates with various detectable moieties wherein a controlled distance exists between the Fc region of the immunoglobulin and the detectable moiety. The conjugates are particularly useful for performing immunoassays, and exhibit improved longevity, specificity and sensitivity.
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19 Claims
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1. A process for producing a derivatized immunoglobulin, said process comprising the steps of:
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(a) site-specifically oxidizing the glycosylated zone of the Fc region of an immunoglobulin with an oxidant to convert at least two hydroxyl groups in said zone of said immunoglobulin to an aldehyde group; (b) reacting the oxidized immunoglobulin of step (a) with a disulfide compound wherein at least one of said aldehyde groups is reductively aminated to introduce a disulfide moiety onto the Fc region of said immunoglobulin; and (c) selectively reducing the disulfide bonds of the disulfide moiety of the reacted immunoglobulin of step (b) with an amount of a reductant sufficient to convert at least one of said disulfide moieties of said immunoglobulin into two sulfhydryl groups but insufficient to reduce the disulfide bonds in the complementarity defined region and the hinge region of said immunoglobulin thereby leaving the disulfide bonds in said complementarity defined region and said hinge region essentially unaffected. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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Specification