Perspective on the Structural Basis for Human Aldo-Keto Reductase 1B10 Inhibition

Area of Science:

• Biochemistry
• Structural Biology
• Medicinal Chemistry

Background:

• Human aldo-keto reductase 1B10 (AKR1B10) is frequently overexpressed in various cancers, contributing to chemoresistance.
• This overexpression positions AKR1B10 as a significant therapeutic target, driving research into novel enzyme inhibitors.

Purpose of the Study:

• To analyze high-resolution crystallographic structures of AKR1B10 with inhibitors.
• To compare these structures with analogous complexes of aldose reductase (AR).
• To identify structural features crucial for developing selective AKR1B10 inhibitors.

Main Methods:

• Comparative crystallographic structure analysis of AKR1B10 and AR.
• Detailed examination of active site features, including anion-binding pockets and transient specificity pockets.
• Investigation of inhibitor-induced conformational changes and the role of enzyme loops.

Main Results:

• Both AKR1B10 and AR possess an anion-binding pocket; inhibitor binding can transiently open a specificity pocket.
• Key structural differences between AKR1B10 and AR involve the alternative conformation of Trp112 and the mobility of loop A.
• Loop A mobility in AKR1B10 creates a larger, more loosely packed subpocket compared to AR.

Conclusions:

• Selective AKR1B10 inhibitors require an anchoring moiety for the anion-binding pocket.
• Inhibitors should maintain the native conformation of Trp112 (AKR1B10-like) and avoid opening the AR specificity pocket.
• Understanding these structural nuances is vital for designing effective AKR1B10-targeted cancer therapies.