1B2H

Oligo-Peptide Binding Protein Complexed with Lysyl-Ornithyl-Lysine

1B2H の概要

• エントリーDOI: 10.2210/pdb1b2h/pdb
• 分子名称: PERIPLASMIC OLIGOPEPTIDE-BINDING PROTEIN, LYS-ORN-LYS, ACETATE ION, ... (5 entities in total)
• 機能のキーワード: peptide binding protein
• 由来する生物種: Salmonella typhimurium
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 61232.78

構造登録者

Davies, T.G.,Tame, J.R.H. (登録日: 1998-11-16, 公開日: 1998-11-16, 最終更新日: 2023-12-27)

主引用文献

Davies, T.G.,Hubbard, R.E.,Tame, J.R.
Relating structure to thermodynamics: the crystal structures and binding affinity of eight OppA-peptide complexes.
Protein Sci., 8:1432-1444, 1999

PubMed Abstract: The oligopeptide-binding protein OppA provides a useful model system for studying the physical chemistry underlying noncovalent interactions since it binds a variety of readily synthesized ligands. We have studied the binding of eight closely related tripeptides of the type Lysine-X-Lysine, where X is an abnormal amino acid, by isothermal titration calorimetry (ITC) and X-ray crystallography. The tripeptides fall into three series of ligands, which have been designed to examine the effects of small changes to the central side chain. Three ligands have a primary amine as the second side chain, two have a straight alkane chain, and three have ring systems. The results have revealed a definite preference for the binding of hydrophobic residues over the positively charged side chains, the latter binding only weakly due to unfavorable enthalpic effects. Within the series of positively charged groups, a point of lowest affinity has been identified and this is proposed to arise from unfavorable electrostatic interactions in the pocket, including the disruption of a key salt bridge. Marked entropy-enthalpy compensation is found across the series, and some of the difficulties in designing tightly binding ligands have been highlighted.

PubMed: 10422831

実験手法

X-RAY DIFFRACTION (1.9 Å)