Hemoglobin with chemically introduced disulfide cross-links and preparation thereof

摘要

Hemoglobin cross-linked with disulfide linkages at sites external to the native globin chains is prepared by reacting hemoglobin with site-directed reagents exemplified by N,N'-bis Cbz-cysteinyl bis (methyl phosphate). Reaction with deoxy hemoglobin produces two main products: cross-linked hemoglobin as the bis cysteinyl amide of the e -amino group of the side chain of Lys-82 of the two b subunits, and modified but non-cross-linked hemoglobin that has each of the same amino groups modified as the cysteinyl amide. Disulfide cross-linked hemoglobin has a variety of uses. The disulfide bonds can be cleaved with reducing agents to give terminal sulfhydryl groups, useful in chemical bonding to sulfhydryl group-containing biochemically active compounds to form conjugates thereof for drug delivery. Hemoglobin cross-linked through disulfide bonds can be formed from the sulfhydryl group terminated reduction products, for use as a hemoglobin-based oxygen carrier.