Structure of the CD33 Receptor and Implications for the Siglec Family.

In the innate immune system, the CD33 receptor modulates microglial activity. Its downregulation promises to slow Alzheimer's disease, and it is already targeted in blood cancers. The mechanism underlying CD33 signaling is unresolved.

Isothermal Titration Calorimetry of Membrane Proteins.

The ability to quantify protein-protein interactions without adding labels to protein has made isothermal titration calorimetry (ITC) a preferred technique to study proteins in aqueous solution. Here, we describe the application of ITC to the study of protein-protein interactions in membrane mimics using the association of integrin αIIb and β3 transmembrane domains in phospholipid bicelles as an example. A higher conceptual and experimental effort compared to water-soluble proteins is required for membrane proteins and rewarded with rare thermodynamic insight into this central class of proteins.