A monoclonal antibody against N-terminus of alpha-atrial natriuretic polypeptide (alpha-ANP): a useful tool for preferential detection of naturally circulating ANP.
A monoclonal antibody directed against the N-terminus of alpha-atrial natriuretic polypeptide (alpha-ANP), named KY-ANP-II, was produced by fusion of a non-producing mouse myeloma cell line, X63-Ag8.653, with spleen cells from a BALB/c mouse immunized with synthetic alpha-human ANP (alpha-hANP) conjugated to bovine thyroglobulin. The obtained antibody showed a high affinity for alpha-hANP with a Ka of 6.6 X 10(10) M-1. With this monoclonal antibody, a specific radioimmunoassay for alpha-hANP was established. The minimal detectable level of alpha-hANP in this radioimmunoassay was 0.8 fmol (2.5 pg)/tube, and IC50 was 8 fmol (25 pg)/tube. The radioimmunoassay recognized alpha-rat ANP on an equimolar basis, whereas there was no detectable cross-reactivity with alpha-ANP [4-28] or alpha-ANP [5-28]. Thus, the monoclonal antibody can detect a hormonal form of ANP, alpha-ANP, but not neuropeptide forms of ANP, alpha-ANP [4-28] and alpha-ANP [5-28]. These results indicate that KY-ANP-II becomes a useful tool for preferential detection of a circulating form of ANP and for investigation of the physiological and pathophysiological significance of ANP as a hormone.
Mukoyama
M
M
Department of Medicine, Kyoto University School of Medicine, Japan.
Nakao
K
K
Yamada
T
T
Itoh
H
H
Sugawara
A
A
Saito
Y
Y
Arai
H
H
Hosoda
K
K
Shirakami
G
G
Morii
N
N
D000818:Animals; D000911:Antibodies, Monoclonal; D009320:Atrial Natriuretic Factor / Q000097:blood*; D003429:Cross Reactions; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D010446:Peptide Fragments / Q000276:immunology*; D011863:Radioimmunoassay
D000911:Antibodies, Monoclonal; D010446:Peptide Fragments; D009320:Atrial Natriuretic Factor