scholarly journals Processing of O-linked Glycosylation in the Chimera Consisting of α-Subunit and Carboxyl-terminal Peptide of the Human Chorionic Gonadotropin β-Subunit is Affected by Dimer Formation with Follicle-stimulating Hormone β-Subunit

2004 ◽  
Vol 51 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Madoka FURUHASHI ◽  
Nobuhiko SUGANUMA
2001 ◽  
Vol 12 (3) ◽  
pp. 191-208 ◽  
Author(s):  
H S Randeva ◽  
A Jackson ◽  
E Karteris ◽  
E W Hillhouse

Human chorionic gonadotropin (hCG) has an essential role in early pregnancy. It is a member of the glycoprotein hormone family also comprising the pituitary derived follicle stimulating hormone (FSH), luteinizing hormone (LH) and thyroid stimulating hormone (TSH). Each hormone consists of a non-covalently bound α and β subunit. Within a species the α subunit is identical and hormone specificity is determined by the unique β subunit.


2008 ◽  
Vol 90 (4) ◽  
pp. 1169-1174 ◽  
Author(s):  
Adriana Lofrano-Porto ◽  
Luiz Augusto Casulari ◽  
Paula P. Nascimento ◽  
Leonardo Giacomini ◽  
Luciana A. Naves ◽  
...  

Endocrinology ◽  
2007 ◽  
Vol 148 (8) ◽  
pp. 3977-3986 ◽  
Author(s):  
Satarupa Roy ◽  
Sunita Setlur ◽  
Rupali A. Gadkari ◽  
H. N. Krishnamurthy ◽  
Rajan R. Dighe

The strategy of translationally fusing the α- and β-subunits of human chorionic gonadotropin (hCG) into a single-chain molecule has been used to produce novel analogs of hCG. Previously we reported expression of a biologically active single-chain analog hCGαβ expressed using Pichia expression system. Using the same expression system, another analog, in which the α-subunit was replaced with the second β-subunit, was expressed (hCGββ) and purified. hCGββ could bind to LH receptor with an affinity three times lower than that of hCG but failed to elicit any response. However, it could inhibit response to the hormone in vitro in a dose-dependent manner. Furthermore, it inhibited response to hCG in vivo indicating the antagonistic nature of the analog. However, it was unable to inhibit human FSH binding or response to human FSH, indicating the specificity of the effect. Characterization of hCGαβ and hCGββ using immunological tools showed alterations in the conformation of some of the epitopes, whereas others were unaltered. Unlike hCG, hCGββ interacts with two LH receptor molecules. These studies demonstrate that the presence of the second β-subunit in the single-chain molecule generated a structure that can be recognized by the receptor. However, due to the absence of α-subunit, the molecule is unable to elicit response. The strategy of fusing two β-subunits of glycoprotein hormones can be used to produce antagonists of these hormones.


1994 ◽  
Vol 130 (1) ◽  
pp. 92-96 ◽  
Author(s):  
Masayoshi Yoshimura ◽  
A Eugene Pekary ◽  
Xuan-Ping Pang ◽  
Loretta Berg ◽  
Laurence A Cole ◽  
...  

Yoshimura M, Pekary AE, Pang X-P, Berg L, Cole LA, Kardana A, Hershman JM. Effect of peptide nicking in the human chorionic gonadotropin β-subunit on stimulation of recombinant human thyroid-stimulating hormone receptors. Eur J Endocrinol 1994;130:92–6. ISSN 0804–4643 It is now generally accepted that human chorionic gonadotropin (hCG) has thyroid-stimulating activity. Heterologous forms of the hCG molecule occur in the purified preparations extracted from urine of pregnant women and patients with trophoblastic diseases. This work was undertaken to determine the effect of peptide nicking in the hCG-β subunit on its thyrotropic potency. Using Chinese hamster ovary cells expressing functional human thyroid-stimulating hormone (TSH) receptors, we examined the effect of nicked hCG on cyclic AMP (cAMP) production and receptor binding. The effect of human leukocyte elastase (hLE), a nicking enzyme, on standard hCG also was examined in the cAMP assay and on receptor binding. We studied five hCG preparations extracted from the urine of normal pregnancy (CR-127 and P8) and trophoblastic diseases (C2, C5 and M4). Two preparations (C2, 96% nicked and M4, 100% nicked in the β44–49 region) showed about a 1.5-fold potency of standard hCG CR-127, which is also 20% nicked in the same region. Non-nicked hCG (P8) had the weakest potency among all of the samples tested. Treatment of standard hCG with hLE increased the cAMP response about two-fold. Dose-dependent displacement of bovine [125I]TSH by standard hCG and hLE-digested hCG was observed and was almost identical. We have confirmed the increased in vitro thyrotropic activity of hCG nicked in the β-intercysteine loop on recombinant human TSH receptors. These data suggest that peptide heterogeneity of the hCG molecule may modulate the in vivo thyrotropic activity of hCG in pregnant women and patients with trophoblastic diseases. Jerome M Hershman, Endocrinology-W111D, West Los Angeles VA Medical Center, Los Angeles, California 90073, USA


PEDIATRICS ◽  
1974 ◽  
Vol 54 (1) ◽  
pp. 42-42
Author(s):  
Robert Penny ◽  
N. Olatunji Olambiwonnu ◽  
S. Douglas Frasier

Penny, R., Olambiwonnu, N. O., and Frasier, S. D.: Follicle stimulating hormone (FSH) and luteinizing hormone-human chorionic gonadotropin (LH-HCG) concentrations in paired maternal and cord sera. Pediatrics, 53:41, 1974. An error was made by the authors under the Materials and Methods section of the above article which appeared in the January issue. The last two sentences should read: To convert to nanograms of LER 907, multiply FSH concentrations by 24 and LH concentrations by 17. For conversion to International Units of commercial HCG, divide LH-HCG concentrations by 0.55.


Sign in / Sign up

Export Citation Format

Share Document