Protein nano-crystallogenesis.

We demonstrate the feasibility of growing crystals of protein in volumes as small as 1 nanoliter. Advances in the handling of very small volumes (i.e.

The prospects of protein nanocrystallography.

The miniaturization of protein crystallography's experimental method has several advantages. Firstly, it reduces the amount of protein required for identifying crystallization conditions, allowing crystallographic studies of rare natural proteins and complexes. Secondly, higher levels of supersaturation can be obtained in very small volumes, allowing the exploration of additional crystallization conditions.

A novel pH-dependent dimerization motif in beta-lactoglobulin from pig (Sus scrofa).

beta-Lactoglobulin (BLG) is a lipocalin and is the major protein in the whey of the milk of cows and other ruminants, but not in all mammalian species. The biological function of BLG is not clear, but a potential role in carrying fatty acids through the digestive tract has been proposed. The capability of BLG to aggregate and form gels is often used to thicken foodstuffs.

Antibody C219 recognizes an alpha-helical epitope on P-glycoprotein.

The ABC transporter, P-glycoprotein, is an integral membrane protein that mediates the ATP-driven efflux of drugs from multidrug-resistant cancer and HIV-infected cells. Anti-P-glycoprotein antibody C219 binds to both of the ATP-binding regions of P-glycoprotein and has been shown to inhibit its ATPase activity and drug binding capacity. C219 has been widely used in a clinical setting as a tumor marker, but recent observations of cross-reactivity with other proteins, including the c-erbB2 protein in breast cancer cells, impose potential limitations in detecting P-glycoprotein.

Crystal structure of the C-terminal SH2 domain of the p85alpha regulatory subunit of phosphoinositide 3-kinase: an SH2 domain mimicking its own substrate.

The binding properties of Src homology-2 (SH2) domains to phosphotyrosine (pY)-containing peptides have been studied in recent years with the elucidation of a large number of crystal and solution structures. Taken together, these structures suggest a general mode of binding of pY-containing peptides, explain the specificities of different SH2 domains, and may be used to design inhibitors of pY binding by SH2 domain-containing proteins. We now report the crystal structure to 1.