Spin Labeling of Surface Cysteines Using a Bromoacrylaldehyde Spin Label.

Unlabelled: Structural investigations of proteins and their biological complexes are now frequently complemented by distance constraints between spin labeled cysteines generated using double electron-electron resonance (DEER) spectroscopy, via site directed spin labeling (SDSL). Methanethiosulfonate spin label (MTSSL), has become ubiquitous in the SDSL of proteins, however, has limitations owing to its high number of rotamers, and reducibility. In this article we introduce the use of bromoacrylaldehyde spin label (BASL) as a cysteine spin label, demonstrating an advantage over MTSSL due to its increased selectivity for surface cysteines, eliminating the need to 'knock out' superfluous cysteine residues.

The open architecture of HD-PTP phosphatase provides new insights into the mechanism of regulation of ESCRT function.

HD-PTP is a tumour suppressor phosphatase that controls endocytosis, down-regulation of mitogenic receptors and cell migration. Central to its role is the specific recruitment of critical endosomal sorting complexes required for transport (ESCRTs). However, the molecular mechanisms that enable HD-PTP to regulate ESCRT function are unknown.

New developments in spin labels for pulsed dipolar EPR.

Spin labelling is a chemical technique that enables the integration of a molecule containing an unpaired electron into another framework for study. Given the need to understand the structure, dynamics, and conformational changes of biomacromolecules, spin labelling provides a relatively non-intrusive technique and has certain advantages over X-ray crystallography; which requires high quality crystals. The technique relies on the design of binding probes that target a functional group, for example, the thiol group of a cysteine residue within a protein.