Journal Issue - Volume 11 Issue 3 (March 2002)
Detecting equilibrium cytochrome c folding intermediates by electrospray ionisation mass spectrometry: Two partially folded forms populate the molten‐globule state
- Rita Grandori
- Published in Wiley Interscience on Jan 01, 2009
- DOI: 10.1110/ps.45102 (p 453-458)
Abstract Nanoelectrospray ionization mass spectrometry (nano‐ESI‐MS) is applied to the characterization of ferric cytochromec (cytc) conformational states under different solvent conditions. The methanol‐induced molten‐globule state in the pH range 2.6–3.0 is found to be populated by two distinct, partially folded conformers IA and IB. The more compact intermediate IB resembles that induced by glycerol in acid‐unfolded cytc. The less compact one, IA, also...
Propagation of a single destabilizing mutation throughout the Escherichia coli ribonuclease HI native state
- Giulietta Spudich, Sonja Lorenz, Susan Marqusee
- Published in Wiley Interscience on Jan 01, 2009
- DOI: 10.1110/ps.37202 (p 522-528)
Abstract A point mutation (I53A) in the core of Escherichia coli RNase H* is known to destabilize both the native conformation (ΔGUN) and the kinetic intermediate (ΔGUI) by 2 kcal/mole. Here, we have used native‐state hydrogen deuterium exchange to ask how this destabilization is propagated throughout the molecule. Stability parameters were obtained for individual residues in I53A and compared with those from the wild‐type protein. A...
Expression, purification, and activities of full‐length and truncated versions of the integral membrane protein Vpu from HIV‐1
- Che Ma, Francesca M. Marassi, David H. Jones, Suzana K. Straus, Stephan Bour, Klaus Strebel, Ulrich Schubert, Myrta Oblatt‐Montal, Mauricio Montal, Stanley J. Opella
- Published in Wiley Interscience on Jan 01, 2009
- DOI: 10.1110/ps.37302 (p 546-557)
Abstract Vpu is an 81‐residue accessory protein of HIV‐1. Because it is a membrane protein, it presents substantial technical challenges for the characterization of its structure and function, which are of considerable interest because the protein enhances the release of new virus particles from cells infected with HIV‐1 and induces the intracellular degradation of the CD4 receptor protein. The Vpu‐mediated enhancement of the virus...
Breaking the singleton of germination protease
- Jimin Pei, Nick V. Grishin
- Published in Wiley Interscience on Jan 01, 2009
- DOI: 10.1110/ps.27302 (p 691-697)
Abstract Germination protease (GPR) plays an important role in the germination of spores of Bacillus and Clostridium species. A few very similar GPRs form a singleton group without significant sequence similarities to any other proteins. Their active site locations and catalytic mechanisms are unclear, despite the recent 3‐D structure determination of Bacillus megaterium GPR. Using structural comparison and sequence analysis, we show that GPR is homologous...
Generation of ligand‐receptor alliances by “SEA” module‐mediated cleavage of membrane‐associated mucin proteins
- Daniel H. Wreschner, Michael A. McGuckin, Stefanie J. Williams, Amos Baruch, Merav Yoeli, Ravit Ziv, Liron Okun, Joseph Zaretsky, Nechama Smorodinsky, Iafa Keydar, Pavlos Neophytou, Martin Stacey, His‐Hsien Lin, Siamon Gordon
- Published in Wiley Interscience on Jan 01, 2009
- DOI: 10.1110/ps.16502 (p 698-706)
Abstract A mechanism is described whereby one and the same gene can encode both a receptor protein as well as its specific ligand. Generation of this receptor–ligand partnership is effected by proteolytic cleavage within a specific module located in a membrane resident protein. It is postulated here that the “SEA” module, found in a number of heavily O‐linked glycosylated membrane‐associated proteins, serves as a site for...
