The Three-dimensional Structure of the Human α2-Macroglobulin Dimer Reveals Its Structural Organization in the Tetrameric Native and Chymotrypsin α2-Macroglobulin Complexes

Three-dimensional electron microscopy reconstructions of the human α2-macroglobulin (α2M) dimer and chymotrypsin-transformed α2M reveal the structural arrangement of the two dimers that comprise native and proteinase-transformed molecules. They consist of two side-by-side extended strands that have a clockwise and counterclockwise twist about their major axes in the native and transformed structures, respectively. This and other studies show...