Masinga Nompilo, Nelson David R, Syed Khajamohiddin
Department of Biochemistry and Microbiology, Faculty of Science, Agriculture and Engineering, University of Zululand, Empangeni 3886, South Africa.
Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
Int J Mol Sci. 2025 Sep 2;26(17):8531. doi: 10.3390/ijms26178531.
Tuberculosis, the deadliest human lung disease caused by , continues to be a global health threat, and finding new drugs and drug targets seems an ongoing battle. The cytochrome P450 CYP125A1 enzyme of H37Rv, which is involved in cholesterol metabolism, is a well-established target for drug development. Research is ongoing to identify new compounds that target this enzyme. Understanding the structure-activity relationship of CYP125 family members is crucial for developing a specific and efficient inhibitor. In this direction, this study analyzed 21 crystal structures of CYP125 family enzymes, unraveling the factors responsible for substrate specificity and the amino acids that play a key role in catalysis. One of the unique features of CYP125A1 is its active site cavity shape, which determines the specificity of substrates and inhibitors. The active site cavity is shaped like a letter box, lined by hydrophobic residues, and it transitions into a funnel-like shape with a progressive narrowing as it approaches the heme. Due to this shape, the cholesterol and cholest-4-en-3-one serve as substrates, but not androstenedione, as the former molecules have an alkyl side chain that extends down the narrow funnel channels, interacting with the heme iron. Different binding patterns were observed for substrates and indole-derived inhibitors. Both type I and type II interactions were observed with the non-azole P450 inhibitor LP10 and indole-derived compounds, where the side chain of the indole-derived compound determined the type of interaction. This study provides a comprehensive understanding of the structure-function analysis of P450 enzymes and the interactions of CYP125A members with various ligands. Our findings pave the way for designing new and specific CYP125A1 inhibitors that will ultimately be developed into novel anti-TB drugs.
结核病是由……引起的最致命的人类肺部疾病，仍然是全球健康威胁，寻找新药物和药物靶点似乎是一场持久战。H37Rv的细胞色素P450 CYP125A1酶参与胆固醇代谢，是药物开发中一个公认的靶点。目前正在进行研究以鉴定靶向该酶的新化合物。了解CYP125家族成员的构效关系对于开发特异性和高效的抑制剂至关重要。在此方向上，本研究分析了CYP125家族酶的21个晶体结构，揭示了负责底物特异性的因素以及在催化中起关键作用的氨基酸。CYP125A1的独特特征之一是其活性位点腔的形状，它决定了底物和抑制剂的特异性。活性位点腔的形状像一个信箱，由疏水残基排列，当它接近血红素时逐渐变窄，转变为漏斗状。由于这种形状，胆固醇和胆甾-4-烯-3-酮作为底物，但雄烯二酮不是，因为前一种分子有一个烷基侧链，它沿着狭窄的漏斗通道向下延伸，与血红素铁相互作用。观察到底物和吲哚衍生抑制剂有不同的结合模式。非唑类P450抑制剂LP10和吲哚衍生化合物都观察到了I型和II型相互作用，其中吲哚衍生化合物的侧链决定了相互作用的类型。本研究全面了解了P450酶的结构-功能分析以及CYP125A成员与各种配体的相互作用。我们的发现为设计新的特异性CYP125A1抑制剂铺平了道路，这些抑制剂最终将被开发成新型抗结核药物。
