N-glycosylation increases the circulatory half-life of human growth hormone

Endocrinology. 2010 Nov;151(11):5326-36. doi: 10.1210/en.2010-0574. Epub 2010 Sep 8.


Therapeutic use of recombinant GH typically involves daily sc injections. We examined the possibilities for prolonging the in vivo circulation of GH by introducing N-glycans. Human GH variants with a single potential N-glycosylation site (N-X-S/T) introduced by site-directed mutagenesis were expressed in HEK293 cells. In a scan of 15 different positions for N-glycosylation sites, four positions (amino acids 93, 98, 99, and 101) were efficiently utilized and did not influence GH in vitro activity. A GH variant (3N-GH) with all these sites was produced in CHOK1SV cells and contained up to three N-glycans. Two pools of 3N-GH were purified and separated according to their charge by anion-exchange chromatography. Anion-exchange HPLC revealed that the N-glycans in the two pools were very similar except for the extent of sialylation. Both 3N-GH pools circulated longer in rats than wild-type GH. The terminal half-life of 3N-GH after iv injection was 24-fold prolonged compared with wild-type GH for the pool with the most pronounced sialylation, 13-fold prolonged for the less sialylated pool, and similar to the wild-type for desialylated 3N-GH. The less sialylated 3N-GH pool exhibited a profound pharmacodynamic effect in GH-deficient rats. Over a 4-d period, a single injection of 3N-GH induced a stronger IGF-I response and a larger increase in body weight than daily injections with wild-type GH. Thus, N-glycans can prolong the in vivo circulation and enhance the pharmacodynamic effect of GH. Sialic acids seem to play a pivotal role for the properties of glycosylated GH.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • Enzyme-Linked Immunosorbent Assay
  • Glycosylation
  • Half-Life
  • Human Growth Hormone / metabolism*
  • Humans
  • Polysaccharides / metabolism*
  • Random Allocation
  • Rats
  • Rats, Sprague-Dawley


  • Polysaccharides
  • Human Growth Hormone