title: Glycosylation of an N-terminal extension prolongs the half-life and increases the in vivo activity of follicle stimulating hormone.
abstract: FSH is a key component in assisted reproductive technologies. Because of rapid clearance of the hormone, patients have to be treated with daily injections. To address this problem, a long-acting FSH mutein was created by introduction of additional N-linked glycosylation into the molecule. New glycosylation sites were introduced by two different approaches: structure-aided, site-directed introduction of sites within the FSH molecule and addition of N-terminal extensions. A mutein with the extension sequence ANITVNITV at the N terminus of the alpha-chain (FSH1208) was efficiently glycosylated at both new sites. This resulted in a molecule with increased size and charge, factors known to reduce renal clearance of proteins. FSH1208 was found to have a 3- to 4-fold increased serum half-life, compared with wild-type recombinant FSH. Furthermore, in spite of a lower in vitro activity, FSH1208 had a markedly increased in vivo potency, as shown by increased ability to augment the ovarian weight and stimulate the serum estradiol levels in rats. These characteristics make FSH1208 a possible candidate for improved infertility treatment.
authors.affiliation: Maxygen, DK-2970 Hoersholm, Denmark.
authors.forename: Signe
authors.initials: S
authors.lastname: Perlman
authors.forename: Bart
authors.initials: B
authors.lastname: van den Hazel
authors.forename: Jesper
authors.initials: J
authors.lastname: Christiansen
authors.forename: Sanne
authors.initials: S
authors.lastname: Gram-Nielsen
authors.forename: Claus B
authors.initials: CB
authors.lastname: Jeppesen
authors.forename: Kim V
authors.initials: KV
authors.lastname: Andersen
authors.forename: Torben
authors.initials: T
authors.lastname: Halkier
authors.forename: Sigurd
authors.initials: S
authors.lastname: Okkels
authors.forename: Hans T
authors.initials: HT
authors.lastname: Schambye
mesh_terms: D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D015195:Drug Design; D004958:Estradiol / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000737:chemistry / Q000235:genetics* / Q000493:pharmacokinetics*; D015870:Gene Expression; D006031:Glycosylation; D006801:Humans; D066298:In Vitro Techniques; D007247:Infertility, Female / Q000188:drug therapy; D009929:Organ Size; D010053:Ovary / Q000033:anatomy & histology / Q000187:drug effects; D017434:Protein Structure, Tertiary; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D004958:Estradiol; D005640:Follicle Stimulating Hormone