4R0B

Structure of dimeric human glycodelin

4R0B の概要

• エントリーDOI: 10.2210/pdb4r0b/pdb
• 分子名称: Glycodelin (2 entities in total)
• 機能のキーワード: amniotic fluid, cumulus oophorus, endometrium, fallopian tube, fertilization, glycan presentation, human lipocalin, lipid binding protein, seminal fluid, sperm-egg binding
• 由来する生物種: Homo sapiens (human)
• 細胞内の位置: Secreted : P09466
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 19657.63

構造登録者

Schiefner, A.,Skerra, A. (登録日: 2014-07-30, 公開日: 2014-12-10, 最終更新日: 2017-11-22)

主引用文献

Schiefner, A.,Rodewald, F.,Neumaier, I.,Skerra, A.
The dimeric crystal structure of the human fertility lipocalin glycodelin reveals a protein scaffold for the presentation of complex glycans.
Biochem.J., 466:95-104, 2015

PubMed Abstract: Human glycodelin (Gd) is an abundant glycoprotein from the lipocalin family and is involved in crucial biological processes such as reproduction and immune reaction. In females and males, Gd is found in four distinct glycoforms-A, C, F and S-that arise from different N-linked oligosaccharide side chains at amino acid residues Asn28 and Asn63. We have expressed Gd (carrying two amino acid substitutions to improve solubility) as a non-glycosylated protein in Escherichia coli via periplasmic secretion and determined its X-ray structure at 2.45 Å resolution. Gd reveals a classical lipocalin fold including two disulfide bridges, which is however unusually compact and lacks a pronounced central pocket inside the β-barrel, in line with its low affinity for hydrophobic ligands. Instead, this lipocalin exhibits a unique homodimeric quaternary structure that appears ideally suited as a scaffold for the presentation of specific glycans. In fact, the four oligosaccharides are presented in close proximity on the same side of the dimer surface, which increases avidity for cellular receptors, e.g. during sperm-egg recognition. A bioinformatic analysis indicated that Gd orthologues exclusively occur in certain suborders of primates that have a menstrual cycle, suggesting that this lipocalin with its role in fertility only recently emerged during evolution.

PubMed: 25422905
DOI: 10.1042/BJ20141003

実験手法

X-RAY DIFFRACTION (2.45 Å)