Fragment Binding to ß-Secretase 1 without Catalytic Aspartate Interactions Identified via Orthogonal Screening Approaches.

An approach to identify ß-secretase 1 (BACE1) fragment binders that do not interact with the catalytic aspartate dyad is presented. A ThermoFluor (thermal shift) and a fluorescence resonance energy transfer enzymatic screen on the soluble domain of BACE1, together with a surface plasmon resonance (SPR) screen on the soluble domain of BACE1 and a mutant of one catalytic Asp (D32N), were run in parallel. Fragments that were active in at least two of these assays were further confirmed using one-dimensional NMR (WaterLOGSY) and SPR binding competition studies with peptidic inhibitor OM99-2. Protein-observed NMR (two-dimensional 15N heteronuclear single-quantum coherence spectroscopy) and crystallographic studies with the soluble domain of BACE1 identified a unique and novel binding mode for compound 12, a fragment that still occupies the active site while not making any interactions with catalytic Asps. This novel approach of combining orthogonal fragment screening techniques, for both wild-type and mutant enzymes, as well as binding competition studies could be generalized to other targets to overcome undesired interaction motifs and as a hit-generation approach in highly constrained intellectual property space.

Accessing Reliable Health Information on the Web: A Review of the HON Approach.

Accessing online health content of high quality and reliability presents challenges. Laypersons cannot easily differentiate trustworthy content from misinformed or manipulated content. This article describes complementary approaches for members of the general public and health professionals to find trustworthy content with as little bias as possible. These include the Khresmoi health search engine (K4E), the Health On the Net Code of Conduct (HONcode) and health trust indicator Web browser extensions.

Health On the Net's 20 Years of Transparent and Reliable Health Information.

The Health On the Net Foundation (HON) was born in 1996, during the beginning of the World Wide Web, from a collective decision by health specialists, led by the late Jean-Raoul Scherrer, who anticipated the need for online trustworthy health information. Because the Internet is a free space that everyone shares, a search for quality information is like a shot in the dark: neither will reliably hit their target. Thus, HON was created to promote deployment of useful and reliable online health information, and to enable its appropriate and efficient use. Two decades on, HON is the oldest and most valued quality marker for online health information. The organization has maintained its reputation through dynamic measures, innovative endeavors and dedication to upholding key values and goals. This paper provides an overview of the HON Foundation, and its activities, challenges, and achievements over the years.

Liquid chromatography-mass spectrometry with chemiluminescent nitrogen detection for on-line quantitative analysis of compound collections: advantages and limitations.

Recently, alternative detection methods such as chemiluminescent nitrogen detection (CLND) have been coupled successfully with HPLC for quantification. This detector produces a signal proportional to the number of moles nitrogen present in the compound. Sample concentration of compounds with a known formula can be determined by use of an external calibration standard such as caffeine. Hence, the CLND can be used without the need for primary standards of the compound with unknown concentration, which enables the use of this detector for high-throughput analysis. In this work, the reliability and pitfalls of this coupled LC-MS/CLND are demonstrated. Nitrogen detection is specific as it only gives a response for nitrogen containing compounds and universal since it only gives a linear response. Nevertheless the lower response for N=N and N-N containing compounds has been evaluated in this study.