J Korean Med Sci.  1989 Dec;4(4):171-177. 10.3346/jkms.1989.4.4.171.

Immunoradiometric assay of human proinsulin and partially processed proinsulin with use of monoclonal antibody and streptavidin-biotin labeling

• Kim JQ
• Cho HI
• Kim SI
• Lee HK
• Hales CN

• KMID: 1421467
• DOI: http://doi.org/10.3346/jkms.1989.4.4.171

Abstract

The sensitive and specific immunoradiometric assay is described for human proinsulin and its intermediate peptides (65-66 split and 32-33 split proinsulin). We developed a monoclonal antibody-based two-site immunoradiometric assay with use of streptavidin-biotin labeling. The detection limits of the assays lie in the range of 0.5-2.0 pM. In the proinsulin assay proinsulin cross-reacted 66% with 65-66 split proinsulin but not with insulin or 32-33 split proinsulin. In the assay of 65-66 split proinsulin it does not cross-react with insulin, proinsulin or 32-33 split proinsulin. In the 32-33 split proinsulin assay it cross-reacted 84% with proinsulin and 60% with 65-66 split proinsulin. The precision (C.V.) of the assays was less than 15% over the various concentration. The mean concentrations of insulin, proinsulin, 65-66 split proinsulin and 32-33 proinsulin in eight young male subjects in the fasting state were (pM +/- S.E.M.) 20 +/- 3.6, 2.3 +/- 0.3, undetectable (less than 1.0) and 2.1 +/- 0.7 and at the maximum reached during an oral glucose tolerance test, 150 +/- 26, 9.9 +/- 1.4, 3.8 +/- 0.6 and 19.7 +/- 6.0 respectively.

Keyword

immunoradiometric assay; monoclonal antibodies; streptavidin-biotin; proinsulin; diabetes

MeSH Terms

Adult
Animals
Antibodies, Monoclonal/*immunology
Bacterial Proteins
Biotin
Cross Reactions
Humans
Immunoradiometric Assay
Male
Mice
Proinsulin/*analysis/immunology
Reproducibility of Results
Streptavidin
Antibodies, Monoclonal
Bacterial Proteins
Biotin
Streptavidin
Proinsulin