1NEJ

Crystalline Human Carbonmonoxy Hemoglobin S (Liganded Sickle Cell Hemoglobin) Exhibits The R2 Quaternary State At Neutral pH In The Presence Of Polyethylene Glycol: The 2.1 Angstrom Resolution Crystal Structure

1NEJ の概要

• エントリーDOI: 10.2210/pdb1nej/pdb
• 関連するPDBエントリー: 1BBB 1HHO 1K1K 1M9P 1RVW
• 分子名称: Hemoglobin alpha chain, Hemoglobin beta chain, PROTOPORPHYRIN IX CONTAINING FE, ... (5 entities in total)
• 機能のキーワード: mutant human hemoglobin s[betae6v]; r2 quaternary state; human hemoglobin, oxygen storage-transport complex, oxygen storage/transport
• 由来する生物種: Homo sapiens (human); 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 64599.13

構造登録者

Patskovska, L.N.,Patskovsky, Y.V.,Almo, S.C.,Hirsch, R.E. (登録日: 2002-12-11, 公開日: 2003-12-16, 最終更新日: 2023-08-16)

主引用文献

Patskovska, L.N.,Patskovsky, Y.V.,Almo, S.C.,Hirsch, R.E.
COHbC and COHbS crystallize in the R2 quaternary state at neutral pH in the presence of PEG 4000.
Acta Crystallogr.,Sect.D, 61:566-573, 2005

PubMed Abstract: Human hemoglobin binds oxygen cooperatively and functions as a tetramer composed of two identical alphabeta heterodimers. While human hemoglobin is the best characterized allosteric protein, the quaternary R (oxygenated or liganded) to T (deoxygenated) structural transition remains controversial. The R2 state has been postulated to represent either an intermediate or final quaternary state elicited by ligand binding. However, the biological relevance of the R2 state has been questioned as it has not been observed crystallographically under physiological conditions. The high-resolution R2 quaternary structures of human COHbC (betaE6K) and COHbS (betaE6V) are reported at neutral pH and low ionic strength using PEG 4000 as a precipitant. Crystals of COHbC, COHbS and their mixtures are isomorphous, indicating that they share the same tertiary and quaternary structures. In contrast, oxyHbA or COHbA did not yield crystals at neutral pH under similar conditions. Solubility studies and modeling suggest that at neutral pH and low ionic strength the beta6 mutant hemoglobins crystallize (betaK6 > betaV6) as a result of more favorable lattice contacts.

PubMed: 15858266
DOI: 10.1107/S0907444905004622

実験手法

X-RAY DIFFRACTION (2.1 Å)