Time-Resolved Tracking of Separately Internalized Neuropeptide Y Receptors by Two-Color Pulse-Chase.

Internalization and intracellular trafficking of G protein-coupled receptors (GPCR) plays an important role in the signal transduction. These processes are often highly dynamic and take place rapidly. In the past 10 years, it became obvious that internalized GPCRs are also capable of signaling via arrestin or heterotrimeric G proteins within the endosomal compartment.

Peptide-tags for site-specific protein labelling in vitro and in vivo.

Peptide-tag based labelling can be achieved by (i) enzymes (ii) recognition of metal ions or small molecules and (iii) peptide-peptide interactions and enables site-specific protein visualization to investigate protein localization and trafficking.

Rapid Covalent Fluorescence Labeling of Membrane Proteins on Live Cells via Coiled-Coil Templated Acyl Transfer.

Fluorescently labeled proteins enable the microscopic imaging of protein localization and function in live cells. In labeling reactions targeted against specific tag sequences, the size of the fluorophore-tag is of major concern. The tag should be small to prevent interference with protein function.

Peptide-templated acyl transfer: a chemical method for the labeling of membrane proteins on live cells.

The development of a method is described for the chemical labeling of proteins which occurs with high target specificity, proceeds within seconds to minutes, and offers a free choice of the reporter group. The method relies upon the use of peptide templates, which align a thioester and an N-terminal cysteinyl residue such that an acyl transfer reaction is facilitated at nanomolar concentrations. The protein of interest is N-terminally tagged with a 22 aa long Cys-E3 peptide (acceptor), which is capable of forming a coiled-coil with a reporter-armed K3 peptide (donor).

Formaldehyde formation on vanadium oxide surfaces V2O3(0001) and V2O5(001): how does the stable methoxy intermediate form?

Hydroxy-mediated methoxy formation or stabilization is probably an important process in many methanol adsorption systems. Hydrogen atoms originating from the scission of the methanol O-H bond react with the substrate and form water. This process may result 1) in the production of additional surface defects as reactive centers for methoxy formation and 2) in the stabilization of methoxy groups by suppression of methanol formation.