Protein-protein conjugation on a lectin matrix

Abstract

An efficient method of protein-protein conjugation yielding primarily monoconjugates is described. A glycoprotein enzyme, invertase, was 'spaced-out' on a succinyl concanavalin A sepharose matrix and reacted with 1% glutaraldehyde. The excess glutaraldehyde was washed out and a second, non-glycoprotein, enzyme, urease, was reacted with the 'activated' invertase. The column was washed till the washings were free of enzymatic activity. On elution with α-methyl glucoside both enzymes were detected in the eluate. Resolution on Sepharose 6B revealed that the eluted invertase was completely conjugated to urease. The molecular size of the conjugate suggested that it was a monoconjugate. The glutaraldehyde treated enzyme retained its immunological reactivity in the conjugate. This method of protein-protein conjugation is applicable if one of the two involved proteins is a glycoprotein.