Screening Using Ultrafiltration and Mass Spectrometry

Library Screening Using Ultrafiltration and Mass Spectrometry 

In the past decade, MS has become an indispensable tool for the pharmaceutical industry at each stage in drug discovery (see Table 4.1 [4]). Primarily, MS has been employed at the drug development stage. However, due to major advances in affinity-based MS technologies, it is readily becoming a common tool for hit identification in the drug discovery process (see Table 4.2 [4]). A common theme 

Phase Numbers of compounds Role or opportunity for MS-based methods 

Initial lead discovery Start with prefer 10-100 hits Limited by massive installed base of other methods. Current paradigm requires only singlepoint estimate of activity, because low-potency hits are expected (therefore, power of MS-based systems may overmatch the task). Mass-based recognition of compounds may be thwarted by isobaric compounds or impurities. 

Lead optimization Start with 1—4 hits expand to 100-1000 by library technology May be optimum location for use of MS at this stage, there is interest in accurately determining the respective affinities of compounds derived from the initial leads. Requires screening shift to a secondary assay that could introduce a lag time following early screening phase. 

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I 4 Library Screening Using Ultrafiltration and Mass Spectrometry... 

Pulsed ultrafiltration MS (PUF-MS) represents an inline high throughput affinity screening method with a variety of potential uses in the discovery and development of pharmaceuticals [22]. The in-line combination of solution-phase equilibration, ultrafiltration, and electrospray liquid chromatography mass spectrometry (LC-ESI-MS) facilitates the identification of high affinity target-specific... 

Pulsed Ultrafiltration-Mass Spectrometry. A versatile approach to screening solution phase combinatorial libraries and natural product extracts is pulsed ultrafiltration-mass spectrometry (61,62), which uses a standard LC-MS system with an ultrafiltration chamber substituted for the HPLC column. 

The advantages of pulsed ultrafiltration-mass spectrometry include the variety of different applications that may be carried out, the convenience of on-line screening, solution-phase screening, the ability to screen either combinatorial libraries or natural product extracts, the diversity of receptors that may be screened, and the freedom to use either volatile or non-volatile binding buffers. For metabolic and toxicity screening, flow injection analyses have the additional advantages that product feedback inhibition is prevented so that the metabolic profile more closely approximates the in vivo system ( 70). Finally, the... 

Gu,C. Nikolic,D. Lai,J. Xu,X. VanBreemen,R.B. Assays of ligand-human serum albumin binding using pulsed ultrafiltration and liquid chromatography-mass spectrometry. Comb. Chem. High Throughput Screen. 1999,2, 353-359. 

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