Chemical Genomics – Biol503 Lecture 4 Other Applications of Chemical Genomics.
-
date post
19-Dec-2015 -
Category
Documents
-
view
220 -
download
1
Transcript of Chemical Genomics – Biol503 Lecture 4 Other Applications of Chemical Genomics.
Chemical Screen Assays
Many chemical screening assays rely on fluorescent strategies to report on enzymatic activities
However, the need for labels may be a detriment due to: Labels can compromise activity of substrates Some enzymatic assays can not be adapted
to fluorescent labels Fluorescent properties of small molecules in
the libraries can lead to false positive signals
MS Methods
Mass Spectrometry based methods avoid the need for labels in analyzing the products of enzymatic reactions because they report on the mass of the substrate, an intrinsic property of every molecule
Min et al. described a class of surfaces that both simplifies sample preparation and gives clear and easily interpretable peaks in MS
They combine self-assembled monolayers (SAMs) with MALDI-TOF mass spectrometry to discover inhibitors of anthrax lethal factor
Anthrax virulence factors
Bacillus anthracis secrete three major virulence factors: Protective antigen, it binds to a TEM-8
cell-surface receptor of the host cell and mediates delivery of edema factor and lethal factor into the cytosol
Edema factor, an ademylate cyclase that causes edema
Lethal factor, a protease that cleaves N terminus of mitogen-activated protein kinase kinase (MAPKK or MEK1)
Microfluidics
Microfluidics deals with the behavior, precise control and manipulation of fluids that are geometrically constrained to a small, typically sub-millimeter, scale.
Quake Group at Stanford developed a microfluidic platform for measuring binding constants by using mechanical trapping of molecular interactions (MITOMI)
Microfluidics
The Quake Group studied RNA binding by the HCV transmembrane protein NS4B
It was shown that NS4B binds RNA and that this binding is specific for the 3’ terminus of the negative strand of the viral genome with a dissociation constant (Kd) of 3.4 nM.
A high throughput microfluidic screen of a compound library identified 18 inhibitors of binding of RNA by NS4B.