Enzyme-linked Immunoassay<subtitle>I. Novel Method for Synthesis of the Insulin-β-D-galactosidase Conjugate and Its Applicability for Insulin Assay</subtitle>

Abstract

Pork insulin was subjected to mercaptosuccinylation and then coupled to beta-D-galactosidase [EC 3.2.1.23] from Escherichia coli using N,N'-o-phenylenedimaleimide. The competitive binding of the conjugate and insulin to anti-insulin antibody was tested. Results showed that formation of an insulin-beta-D-galactosidase conjugate could be used for immunoassay of insulin.