1ZO9

Crystal Structure Of The Wild Type Heme Domain Of P450BM-3 with N-palmitoylmethionine

1ZO9 の概要

• エントリーDOI: 10.2210/pdb1zo9/pdb
• 関連するPDBエントリー: 1BU7 1JPZ 1ZO4 1ZOA 2HPD
• 分子名称: Bifunctional P-450:NADPH-P450 reductase, PROTOPORPHYRIN IX CONTAINING FE, N-PALMITOYL-L-METHIONINE, ... (6 entities in total)
• 機能のキーワード: cytochrome p-450, wild type heme protein, oxidoreductase
• 由来する生物種: Bacillus megaterium
• 細胞内の位置: Cytoplasm (By similarity): P14779
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 111484.85

構造登録者

Hegda, A.,Chen, B.,Tomchick, D.R.,Bondlela, M.,Haines, D.C.,Schaffer, N.,Machius, M.,Graham, S.E.,Peterson, J.A. (登録日: 2005-05-12, 公開日: 2006-08-01, 最終更新日: 2023-08-23)

主引用文献

Hegde, A.,Haines, D.C.,Bondlela, M.,Chen, B.,Schaffer, N.,Tomchick, D.R.,Machius, M.,Nguyen, H.,Chowdhary, P.K.,Stewart, L.,Lopez, C.,Peterson, J.A.
Interactions of substrates at the surface of P450s can greatly enhance substrate potency.
Biochemistry, 46:14010-14017, 2007

PubMed Abstract: Cytochrome P450s are a superfamily of heme containing enzymes that use molecular oxygen and electrons from reduced nicotinamide cofactors to monooxygenate organic substrates. The fatty acid hydroxylase P450BM-3 has been particularly widely studied due to its stability, high activity, similarity to mammalian P450s, and presence of a cytochrome P450 reductase domain that allows the enzyme to directly receive electrons from NADPH without a requirement for additional redox proteins. We previously characterized the substrate N-palmitoylglycine, which found extensive use in studies of P450BM-3 due to its high affinity, high turnover number, and increased solubility as compared to fatty acid substrates. Here, we report that even higher affinity substrates can be designed by acylation of other amino acids, resulting in P450BM-3 substrates with dissociation constants below 100 nM. N-Palmitoyl-l-leucine and N-palmitoyl-l-methionine were found to have the highest affinity, with dissociation constants of less than 8 nM and turnover numbers similar to palmitic acid and N-palmitoylglycine. The interactions of the amino acid side chains with a hydrophobic pocket near R47, as revealed by our crystal structure determination of N-palmitoyl-l-methionine bound to the heme domain of P450BM-3, appears to be responsible for increasing the affinity of substrates. The side chain of R47, previously shown to be important in interactions with negatively charged substrates, does not interact strongly with N-palmitoyl-l-methionine and is found positioned at the enzyme-solvent interface. These are the tightest binding substrates for P450BM-3 reported to date, and the affinity likely approaches the maximum attainable affinity for the binding of substrates of this size to P450BM-3.

PubMed: 18004886
DOI: 10.1021/bi701667m

実験手法

X-RAY DIFFRACTION (1.7 Å)