PROTEIN-BORONIC ACID CONJUGATES AND THEIR BINDING TO LOW-MOLECULAR-MASS CIS-DIOLS AND GLYCATED HEMOGLOBIN

Different methods for covalent linkage of phenylboronic acid (PEA) to structural proteins and enzymes are presented. Protein-PEA conjugates, free in solution or immobilised on magnetizable polymer particles, we re tested for their binding of D-sorbitol, D-mannose and glycohemoglob in (GHb). Similarly, alkaline phosphatase-PBA conjugates were used in an attempted enzyme-linked sorbent assay for the detection of GHb. Aff inity chromatography on immobilised D-mannose and gel chromatographic studies of protein-PEA complexes with [C-14]sorbitol, clearly illustra ted a low affinity of the interaction studied. Glycated hemoglobin cou ld not be detected using the enzyme-linked sorbent assay approach. How ever, GHb was found to be specifically retained on columns filled with protein-PEA-coated particles as affinity matrix, enabling the glycati on level of blood samples to be determined.