Scholarlink

<p>Steroidal medicines are a vital class of pharmaceuticals, with their active ingredients primarily derived from natural steroids. A key step in their biosynthesis involves the isomerization of ∆<sup>5</sup>−3-ketosteroids to ∆<sup>4</sup>−3-ketosteroids, catalyzed by ketosteroid isomerase (KSI). In this study, we discover that KSI exhibits an unexpected catalytic promiscuity, efficiently converting cyclic enones into homo- and hetero-addition products. Crystal structures of KSI variants and mutagenesis reveal the homo-dimeric interface as another active center. Molecular dynamics simulations and quantum mechanics/molecular mechanics calculations suggest a cascade catalytic mechanism by a single enzyme, in which isomerization occurs in the monomeric pocket, while the addition reaction preferentially occurs at the homo-dimeric interface due to reduced steric hindrance. These results not only provide valuable insights into the catalytic diversity of KSIs, but also inspire further exploration of new-to-nature and diverse catalytic properties of enzymes, thus expanding their applications in biocatalysis and drug development.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Catalytic Promiscuity and Cascade Reaction Mechanism of Ketosteroid Isomerases for Addition Reactions of Cyclic Enones

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年7月2日

查看全文
  • Xuemei Li,
  • Mengsha Li,
  • Yangyang Chen,
  • Weidong Liu,
  • Yiyin Liu,
  • Rui Zhang,
  • Chuanfang Wu,
  • Xiang Sheng,
  • Jinku Bao,
  • Jinhui Feng,
  • Qiaqing Wu,
  • Dunming Zhu

摘要

Steroidal medicines are a vital class of pharmaceuticals, with their active ingredients primarily derived from natural steroids. A key step in their biosynthesis involves the isomerization of ∆5−3-ketosteroids to ∆4−3-ketosteroids, catalyzed by ketosteroid isomerase (KSI). In this study, we discover that KSI exhibits an unexpected catalytic promiscuity, efficiently converting cyclic enones into homo- and hetero-addition products. Crystal structures of KSI variants and mutagenesis reveal the homo-dimeric interface as another active center. Molecular dynamics simulations and quantum mechanics/molecular mechanics calculations suggest a cascade catalytic mechanism by a single enzyme, in which isomerization occurs in the monomeric pocket, while the addition reaction preferentially occurs at the homo-dimeric interface due to reduced steric hindrance. These results not only provide valuable insights into the catalytic diversity of KSIs, but also inspire further exploration of new-to-nature and diverse catalytic properties of enzymes, thus expanding their applications in biocatalysis and drug development.