Human transmembrane serine protease 2 (TMPRSS2) is an important member of the type 2 transmembrane serine protease (TTSP) family with significant therapeutic markings. The search for potent TMPRSS2 inhibitors against severe acute respiratory syndrome coronavirus 2 infection with favorable tissue specificity and off-site toxicity profiles remains limited. Therefore, probing the anti-TMPRSS2 potential of enhanced drug delivery systems, such as nanotechnology and prodrug systems, has become compelling. We report the first in silico study of TMPRSS2 against a prodrug, [isopropyl(S)-2-((S)-2-acetamido-3-(1H-indol-3-yl)-propanamido)-6-diazo-5-oxo-hexanoate] also known as DRP-104 synthesized from 6-Diazo-5-oxo-l-norleucine (DON). We performed comparative studies on DON and DRP-104 against a clinically potent TMPRSS2 inhibitor, nafamostat, and a standard serine protease inhibitor, 4-(2-Aminoethyl) benzenesulfonyl fluoride (AEBSF) against TMPRSS2 and found improved TMPRSS2 inhibition through synergistic binding of the S1/S1' subdomains. Both DON and DRP-104 had better thermodynamic profiles than AEBSF and nafamostat. DON was found to confer structural stability with strong positive correlated inter-residue motions, whereas DRP-104 was found to confer kinetic stability with restricted residue displacements and reduced loop flexibility. Interestingly, the Scavenger Receptor Cysteine-Rich (SRCR) domain of TMPRSS2 may be involved in its inhibition mechanics. Two previously unidentified loops, designated X (270−275) and Y (293−296) underwent minimal and major structural transitions, respectively. In addition, residues 273−277 consistently transitioned to a turn conformation in all ligated systems, whereas unique transitions were identified for other transitioning residue groups in each TMPRSS2-inhibitor complex. Intriguingly, while both DON and DRP-104 showed similar loop transition patterns, DRP-104 preserved loop structural integrity. As evident from our systematic comparative study using experimentally/clinically validated inhibitors, DRP-104 may serve as a potent and novel TMPRSS2 inhibitor and warrants further clinical investigation.

中文翻译：

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DON/DRP-104 作为与 SARS-CoV-2 感染有关的有效丝氨酸蛋白酶抑制剂：与人 TMPRSS2 的比较结合模式和新的治疗方法

人跨膜丝氨酸蛋白酶 2 (TMPRSS2) 是 2 型跨膜丝氨酸蛋白酶 (TTSP) 家族的重要成员，具有重要的治疗标记。针对严重急性呼吸综合征冠状病毒 2 感染、具有良好的组织特异性和场外毒性特征的有效 TMPRSS2 抑制剂的搜索仍然有限。因此，探索增强型药物递送系统（例如纳米技术和前药系统）的抗 TMPRSS2 潜力已变得引人注目。我们报告了TMPRSS2针对前药[异丙基(S)-2-((S)-2-acetamido-3-(1H-indol-3-yl)-propanamido)-6-diazo-5的首次计算机模拟研究[-氧代-己酸]也称为 DRP-104，由 6-重氮-5-氧代-1-正亮氨酸 (DON) 合成。我们对 DON 和 DRP-104 与临床有效的 TMPRSS2 抑制剂 nafamostat 和标准丝氨酸蛋白酶抑制剂 4-(2-氨基乙基) 苯磺酰氟 (AEBSF) 对 TMPRSS2 进行了比较研究，发现通过协同结合可改善 TMPRSS2 抑制。 S1/S1' 子域。DON 和 DRP-104 均比 AEBSF 和 nafamostat 具有更好的热力学曲线。研究发现 DON 具有强正相关残基间运动的结构稳定性，而 DRP-104 具有限制残基位移和降低环柔韧性的动力学稳定性。有趣的是，TMPRSS2 的清道夫受体富含半胱氨酸 (SRCR) 结构域可能参与其抑制机制。两个先前未识别的环，指定为 X (270−275) 和 Y (293−296)，分别经历了最小和主要的结构转变。此外，在所有连接系统中，残基 273−277 始终转变为转角构象，而每个 TMPRSS2 抑制剂复合物中的其他转变残基组都鉴定出独特的转变。有趣的是，虽然 DON 和 DRP-104 都显示出相似的环转变模式，但 DRP-104 保留了环结构的完整性。从我们使用经过实验/临床验证的抑制剂进行的系统比较研究可以明显看出，DRP-104 可能作为一种有效的新型 TMPRSS2 抑制剂，值得进一步的临床研究。