Single-particle cryo-electron microscopy (cryo-EM) has emerged as the preferred method for determining the structures of integral membrane proteins at high resolution. However, many membrane proteins are too small or lack distinct structural features, making reliable particle alignment challenging.

Enhancing Cryo-EM with Nanobody-Based Solutions

To overcome these challenges, researchers increasingly use single-domain antibodies (nanobodies) and their synthetic counterparts, sybodies, to stabilize membrane transporters in specific conformations, increase particle size, and serve as fiducial markers for improved alignment.

Recent innovations have led to the development of Legobody and NabFab, engineered antibody fragments that rigidly enlarge nanobodies at their backside. These enhancements further improve structural determination by providing additional stability and alignment benefits.

Sybody Adaptation for Cryo-EM Applications

A key advancement is the ability to harmonize Legobodies and NabFabs with sybodies. Research shows that any sybody can be adapted to the Legobody approach with minimal modifications. However, only a specific subset of sybodies from the loop library can be directly converted into a NabFab-compatible format without requiring complementarity-determining region (CDR) grafting.

Optimizing Structural Studies for Membrane Proteins

These findings streamline the use of Legobodies and NabFabs in synergy with sybodies, expanding their application in structural biology. By improving high-resolution cryo-EM imaging, these tools enhance the study of membrane proteins and other small proteins, paving the way for breakthroughs in drug discovery and therapeutic development.

Stay tuned for more insights into the latest advancements in nanobody technology and cryo-EM structure determination!

Reference: Nature