Glycosylation of an N-terminal extension prolongs the half-life and increases the in vivo activity of follicle stimulating hormone.
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.
Perlman
Signe
S
Maxygen, DK-2970 Hoersholm, Denmark.
van den Hazel
Bart
B
Christiansen
Jesper
J
Gram-Nielsen
Sanne
S
Jeppesen
Claus B
CB
Andersen
Kim V
KV
Halkier
Torben
T
Okkels
Sigurd
S
Schambye
Hans T
HT
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
D004958:Estradiol; D005640:Follicle Stimulating Hormone