Electron microscopy of native cartilage oligomeric matrix protein purified from the Swarm rat chondrosarcoma reveals a five-armed structure.

TLDR

Cartilage oligomeric matrix protein was isolated from Swarm rat chondrosarcoma using selective EDTA extraction and examined by electron microscopy with rotary shadowing and negative staining. The EM images revealed a bouquet‑like protein with five 28‑nm arms converging into a central cylindrical assembly, each arm comprising a peripheral globular domain, a flexible strand, and a central assembly domain.

Abstract

Cartilage oligomeric matrix protein was isolated in the native state from the Swarm rat chondrosarcoma. A crucial step was its selective extraction with EDTA-containing buffer. The purified protein was subjected to electron microscopy using rotary shadowing and negative stain. The images allowed the construction of a structural model. The bouquet-like protein consists of five 28-nm-long arms containing a peripheral globular domain, a flexible strand, and a central assembly domain, where the five arms meet in a cylindrical structure.