title: Development and characterization of a long-acting recombinant hFSH agonist.
abstract: BACKGROUND
  Fusion of the carboxyterminal peptide (CTP) of hCG to FSH results in a follitropin agonist with an extended half-life, presumably due to the four O-oligosaccharides on the CTP. Alternatively, an rhFSH analogue containing additional N-linked carbohydrate is described in this report.
  
  
  METHODS
  A DNA sequence containing two N-oligosaccharide signal sequences was ligated into a vector containing hFSHbeta- and alpha-subunit encoding cDNA, and expressed in CHO-K1 cells. In-vitro bioactivity of the single-chain hormone was assessed in CHO cells expressing the hFSH receptor. Pharmacokinetic values were derived from serial serum assays of the analogue in immature female rats following a single i.v. injection. In-vivo bioactivity was assessed by measuring ovarian weight gain 3 days post-injection.
  
  
  RESULTS
  rhFSH-N2 and native rhFSH induced comparable levels of cAMP in vitro. t(1/2) for native rhFSH, rhFSH-CTP and rhFSH-N2 were 3.7, 7.1 and 7.3 h respectively. Rats receiving rhFSH-N2 had a mean +/- SD ovarian weight 3 days post-i.v. injection (22 +/- 3.6 mg) significantly greater than rats receiving rhFSH and saline (16.7 +/- 1.5 and 15.3 +/- 0.47 mg respectively, P < 0.05).
  
  
  CONCLUSIONS
  rhFSH-N2 has prolonged half-life and increased bioactivity compared with native rhFSH. This rhFSH agonist, and other analogues containing additional N-oligosaccharides may have important clinical applications.
authors.affiliation: Department of Obstetrics and Gynecology and Center for Reproductive Sciences, School of Public Health, Columbia University, New York, NY 10032, USA.
authors.forename: J
authors.initials: J
authors.lastname: Klein
authors.forename: L
authors.initials: L
authors.lastname: Lobel
authors.forename: S
authors.initials: S
authors.lastname: Pollak
authors.forename: B
authors.initials: B
authors.lastname: Lustbader
authors.forename: R T
authors.initials: RT
authors.lastname: Ogden
authors.forename: M V
authors.initials: MV
authors.lastname: Sauer
authors.forename: J W
authors.initials: JW
authors.lastname: Lustbader
mesh_terms: D000818:Animals; D016466:CHO Cells; D002999:Clone Cells; D006224:Cricetinae; D000242:Cyclic AMP / Q000378:metabolism; D005260:Female; D005640:Follicle Stimulating Hormone / Q000819:agonists* / Q000235:genetics*; D006207:Half-Life; D006801:Humans; D007275:Injections, Intravenous; D008596:Menotropins / Q000235:genetics*; D009929:Organ Size / Q000187:drug effects; D010053:Ovary / Q000033:anatomy & histology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage / Q000737:chemistry* / Q000494:pharmacology*; D013678:Technology, Pharmaceutical; D013997:Time Factors
chemical_list: D011993:Recombinant Fusion Proteins; D008596:Menotropins; D005640:Follicle Stimulating Hormone; D000242:Cyclic AMP