一项分子动力学模拟研究，旨在了解胆固醇和组织因子棕榈酰化对不同脂质环境中组织因子-因子 VIIa-因子 Xa 三元复合物的影响。

A molecular dynamics simulation study to understand the effect of cholesterol and tissue factor palmitoylation on tissue factor-factor VIIa-factor Xa ternary complex in different lipid environments.

机构信息

School of Biological Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, India.

出版信息

J Thromb Haemost. 2023 Apr;21(4):917-932. doi: 10.1016/j.jtha.2022.12.020. Epub 2022 Dec 29.

DOI:10.1016/j.jtha.2022.12.020

PMID:36696201

Abstract

BACKGROUND

Tissue factor (TF), a transmembrane glycoprotein, plays a profound role in the formation of the tissue factor-factor VIIa (TF-FVIIa) complex that initiates factor Xa (FXa) generation followed by thrombin activation and clot formation. Previous reports suggest that TF-FVIIa coagulant activity at the cell surface may be affected by various processes, including changes in cholesterol content and posttranslational modifications of TF. Numerous studies were conducted but yielded inconclusive results about the effect of cholesterol on TF expression.

OBJECTIVE

The present study aimed to understand how cholesterol affects structural modulations on the tissue factor-factor VIIa-factor Xa ternary complex (TF-FVIIa-FXa). Additionally, we aimed to illustrate the effect of palmitoylation on the Cys245 residue of TF and understand its structural implications on the TF-FVIIa-FXa.

METHODS

We set up the following 4 systems in different lipid environments: TF-FVIIa-FXa in POPC:POPS (CS), TF-FVIIa-FXa in POPC:POPS:CHOL (CSL), Palmitoylated TF-FVIIa-FXa in POPC:POPS:CHOL (CSLP), and Palmitoylated TF-FVIIa-FXa in POPC:CHOL (CLP), respectively, and subjected them to molecular dynamics simulation.

RESULTS

Hydrogen-bond and contact probability analysis were performed between various important domains of TF-FVIIa-FXa and notable novel interactions: Asn93-Lys48, Arg178-Asp95, Lys20-Glu193, Arg178-Asp97, and Arg153-Gln135 have been reported. The protein stability study implies that the CS and CLP systems are thermodynamically less stable than CSL and CSLP systems.

CONCLUSION

Analysis of molecular dynamic simulation data suggests that the presence of cholesterol and palmitoylation may contribute to structural rigidity, stability, and compactness of key domains of TF-FVIIa-FXa by augmenting protein-protein and protein-lipid interactions.

摘要

背景

组织因子（TF）是一种跨膜糖蛋白，在组织因子-因子 VIIa（TF-FVIIa）复合物的形成中起着重要作用，该复合物启动因子 Xa（FXa）的生成，随后激活凝血酶并形成血栓。先前的报告表明，细胞表面的 TF-FVIIa 凝血活性可能受到多种过程的影响，包括胆固醇含量的变化和 TF 的翻译后修饰。尽管进行了许多研究，但关于胆固醇对 TF 表达的影响仍未有定论。

目的

本研究旨在了解胆固醇如何影响组织因子-因子 VIIa-因子 Xa 三元复合物（TF-FVIIa-FXa）的结构调节。此外，我们旨在说明棕榈酰化对 TF 的 Cys245 残基的影响，并了解其对 TF-FVIIa-FXa 的结构意义。

方法

我们在不同的脂质环境中建立了以下 4 个系统：POPC：POPS（CS）中的 TF-FVIIa-FXa、POPC：POPS：CHOL（CSL）中的 TF-FVIIa-FXa、POPC：POPS：CHOL 中的棕榈酰化 TF-FVIIa-FXa（CSLP）和 POPC：CHOL 中的棕榈酰化 TF-FVIIa-FXa（CLP），并对它们进行了分子动力学模拟。

结果

对 TF-FVIIa-FXa 的各个重要结构域之间的氢键和接触概率进行了分析，并发现了一些新的相互作用：Asn93-Lys48、Arg178-Asp95、Lys20-Glu193、Arg178-Asp97 和 Arg153-Gln135。蛋白质稳定性研究表明，CS 和 CLP 系统在热力学上不如 CSL 和 CSLP 系统稳定。