Immunoradiometric assay of human proinsulin and partially processed proinsulin with use of monoclonal antibody and streptavidin-biotin labeling.
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.
Kim
J Q
JQ
Department of Clinical Pathology, Seoul National University College of Medicine, Korea.
Cho
H I
HI
Kim
S I
SI
Lee
H K
HK
Hales
C N
CN
D000328:Adult; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D001426:Bacterial Proteins; D001710:Biotin; D003429:Cross Reactions; D006801:Humans; D015592:Immunoradiometric Assay; D008297:Male; D051379:Mice; D011384:Proinsulin / Q000032:analysis* / Q000276:immunology; D015203:Reproducibility of Results; D019809:Streptavidin
D000911:Antibodies, Monoclonal; D001426:Bacterial Proteins; D001710:Biotin; D019809:Streptavidin; D011384:Proinsulin