Helen F. Webb

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Site-specific pK(a) values measured by NMR spectroscopy provide essential information on protein electrostatics, the pH-dependence of protein structure, dynamics and function, and constitute an important benchmark for protein pK(a) calculation algorithms. Titration curves can be measured by tracking the NMR chemical shifts of several reporter nuclei versus(More)
The study of anatomy in England during the 18th and 19th century has become infamous for bodysnatching from graveyards to provide a sufficient supply of cadavers. However, recent discoveries have improved our understanding of how and why anatomy was studied during the enlightenment, and allow us to see the context in which dissection of the human body took(More)
High-resolution and accurate Digital Elevation Model (DEM) generation from satellite imagery is a challenging problem. In this work, a stereo 3-D reconstruction framework is outlined that is applicable to nonstereoscopic satellite image pairs that may be captured by different satellites. The orthographic height maps given by stereo reconstruction are(More)
The stability of serine proteases is of major importance for their application in industrial processes. Here we study the determinants of the stability of a Nocardiopsis prasina serine protease using fast residual activity assays, a feature classification algorithm, and structure-based energy calculation algorithms for 121 micropurified mutant enzyme clones(More)
Ubiquitin-conjugating enzymes (E2s or Ubcs) are essential components in the ubiquitination apparatus. These enzymes accept ubiquitin from an E1 enzyme and then, usually with the aid of an E3 enzyme, donate the ubiquitin to the target protein. The function of E2 relies critically on the chemistry of its active site cysteine residue since this residue must(More)
OBJECTIVES To investigate changing nutritional demographics of treated HIV-1-infected patients and explore causes of obesity, particularly in women of African origin. METHODS We prospectively reviewed nutritional demographics of clinic attenders at an urban European HIV clinic during four one-month periods at three-yearly intervals (2001, 2004, 2007, and(More)
Post-exposure prophylaxis after sexual exposure (PEPSE) awareness was audited in an HIV-positive cohort. A total of 403 out of 828 (48.7%) patients were PEPSE aware. Patients diagnosed post-2006 were more PEPSE aware; 57.2% vs. 44.2% (p = 0.0004). Men who have sex with men (MSM) were more PEPSE aware; 65.8% vs. 39.1% in heterosexuals (p < 0.0001).Younger(More)
NMR-monitored pH titration experiments are routinely used to measure site-specific protein pKa values. Accurate experimental pKa values are essential in dissecting enzyme catalysis, in studying the pH-dependence of protein stability and ligand binding, in benchmarking pKa prediction algorithms, and ultimately in understanding electrostatic effects in(More)
Modern satellites tag their images with geolocation information using GPS and star tracking systems. Depending on the quality of the geopositioning equipment, errors may range from a few meters to tens of meters on the ground. At the current state of art, there is no established method to automatically correct these errors limiting the large-scale joint(More)