Charge effects in the selection of NPF motifs by the EH domain of EHD1.

The Eps15 homology (EH) domain is found in proteins associated with endocytosis and vesicle trafficking. EH domains bind to their target proteins through an asparagine-proline-phenylalanine (NPF) motif. We have measured the interaction energetics of the EH domain from EHD1 with peptides derived from two of its binding partners: Rabenosyn-5 (Ac-GPSLNPFDEED-NH(2)) and Rab11-Fip2 (Ac-YESTNPFTAK-NH(2)).

High yield expression and purification of HIV-1 Tat1-72 for structural studies.

The HIV-1 transactivator of transcription (Tat) is a protein essential for virus replication. Tat is an intrinsically disordered RNA-binding protein that, in cooperation with host cell factors cyclin T1 and cyclin-dependent kinase 9, regulates transcription at the level of elongation. Tat also interacts with numerous other intracellular and extracellular proteins, and is implicated in a number of pathogenic processes.

Disorder and structure in the Rab11 binding domain of Rab11 family interacting protein 2.

Rab11 plays a central role in plasma membrane recycling which returns cellular receptors for reuse at the cell surface. A recently identified family of Rab11 interacting proteins (FIP) includes FIP2. The C-terminal region of FIP2 is essential for colocalization with Rab11 on early endosomes and for enabling formation of higher-order oligomers.

Solution structure of the hDlg/SAP97 PDZ2 domain and its mechanism of interaction with HPV-18 papillomavirus E6 protein.

The E6 protein from high-risk types of human papillomavirus (HPV) binds PDZ-domain containing proteins and targets them for degradation. We used isothermal titration calorimetry to measure the interaction of a peptide from the C-terminus of HPV-18 E6 to the second PDZ domain (PDZ2) from the human homologue of the Drosophila discs large tumor suppressor protein (hDlg). Isothermal titration calorimetry experiments with a series of peptides showed that HPV-18 E6 bound hDlg PDZ2 about 5-fold stronger than HPV-16 E6, that the contribution of Arg154 to binding was about 1 kcal/mol, and that the binding was disabled by phosphorylation at Thr156.

Synthesis and characterization of constrained peptidomimetic dipeptidyl peptidase IV inhibitors: amino-lactam boroalanines.

We describe here the epimerization-free synthesis and characterization of a new class of conformationally constrained lactam aminoboronic acid inhibitors of dipeptidyl peptidase IV (DPP IV; E.C. 3.

Identification of a region of fast skeletal troponin T required for stabilization of the coiled-coil formation with troponin I.

We have previously identified evolutionarily conserved heptad hydrophobic repeat (HR) domains in all isoprotein members of troponin T (TnT) and troponin I (TnI), two subunits of the Ca(2+)-regulatory troponin complex. Our suggestion that the HR domains are involved in the formation of a coiled-coil heterodimer of TnT and TnI has been recently confirmed by the crystal structure of the core domain of the human cardiac troponin complex. Here we studied a series of recombinant deletion mutants of the fast skeletal TnT to determine the minimal sequence required for stable coiled-coil formation with the HR domain of the fast skeletal TnI.