1T7X

Zn-alpha-2-glycoprotein; refolded CHO-ZAG PEG 400

1T7X の概要

• エントリーDOI: 10.2210/pdb1t7x/pdb
• 関連するPDBエントリー: 1ZAG 1t7v 1t7w 1t7y 1t7z 1t80
• 分子名称: Zinc-alpha-2-glycoprotein, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, 2-acetamido-2-deoxy-beta-D-glucopyranose (3 entities in total)
• 機能のキーワード: mhc class i homolog, lipid binding protein
• 由来する生物種: Homo sapiens (human)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 32831.56

構造登録者

Delker, S.L.,West Jr., A.P.,McDermott, L.,Kennedy, M.W.,Bjorkman, P.J. (登録日: 2004-05-11, 公開日: 2004-12-21, 最終更新日: 2024-10-30)

主引用文献

Delker, S.L.,West Jr., A.P.,McDermott, L.,Kennedy, M.W.,Bjorkman, P.J.
Crystallographic studies of ligand binding by Zn-alpha2-glycoprotein.
J.Struct.Biol., 148:205-213, 2004

PubMed Abstract: Zn-alpha2-glycoprotein (ZAG) is a 41 kDa soluble protein that is present in most bodily fluids. The previously reported 2.8 A crystal structure of ZAG isolated from human serum demonstrated the structural similarity between ZAG and class I major histocompatibility complex (MHC) molecules and revealed a non-peptidic ligand in the ZAG counterpart of the MHC peptide-binding groove. Here we present crystallographic studies to explore further the nature of the non-peptidic ligand in the ZAG groove. Comparison of the structures of several forms of recombinant ZAG, including a 1.95 A structure derived from ZAG expressed in insect cells, suggests that the non-peptidic ligand in the current structures and in the structure of serum ZAG is a polyethylene glycol (PEG), which is present in the crystallization conditions used. Further support for PEG binding in the ZAG groove is provided by the finding that PEG displaces a fluorophore-tagged fatty acid from the ZAG binding site. From these results we hypothesize that our purified forms of ZAG do not contain a bound endogenous ligand, but that the ZAG groove is capable of binding hydrophobic molecules, which may relate to its function.

PubMed: 15477100
DOI: 10.1016/j.jsb.2004.04.009

実験手法

X-RAY DIFFRACTION (3.1 Å)