High molecular weight growth hormone (> 160 kD) in human serum characterized with monoclonal antibodies.
Human growth hormone (hGH) was analyzed by six monoclonal antibodies (Mabs) and a polyclonal antiserum (Pas) before and after molecular sieve chromatography of sera from healthy subjects. Their hGH levels were between < 0.2 and 0.4 ng/ml as determined with Pas. The six Mabs reacted with five distinct epitopes and bound to a hGH fragment corresponding to the amino acid sequence 15-125. Two of the Mabs showed reduced binding to 20-kD hGH. The binding of Mabs to dimeric forms of hGH varied. Human GH levels in unfractionated sera as determined with Mabs were < 3.1-390 ng/ml. After molecular sieve chromatography of the sera, one peak of hGH-immunoreactive material of high molecular weight (> 160 kD) and one at the elution volume of monomeric hGH were determined with Pas and Mabs. The major part of the high molecular weight hGH (> 160 kD) seemed to consist of 22-kD hGH molecules, since Pas and all Mabs detected the hGH immunoreactivity (> 160 kD) in a similar manner. This high molecular weight hGH (> 160 kD) was distinguishable from the identified, receptor-like hGH-binding protein in serum.
Jónsdóttir
I
I
Department of Immunology, University of Stockholm, Sweden.
Luthman
M
M
Ekre
H P
HP
Skoog
B
B
Brostedt
P
P
Roos
P
P
Werner
S
S
Perlmann
P
P
D000328:Adult; D000911:Antibodies, Monoclonal; D002850:Chromatography, Gel; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes; D013006:Growth Hormone / Q000097:blood* / Q000737:chemistry / Q000276:immunology; D006801:Humans; D008297:Male; D008970:Molecular Weight; D011863:Radioimmunoassay
D000911:Antibodies, Monoclonal; D000939:Epitopes; D013006:Growth Hormone