Biophysical approaches in a structure-guided SMYD3 ligand discovery
Typ
Examensarbete för masterexamen
Program
Biotechnology (MPBIO), MSc
Publicerad
2019
Författare
Talu, Martin Johannes
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
In eukaryotic cells, DNA is wrapped around nucleosomal cores formed of protein
heterooctamers, which consist of core histones. Nucleosomes are the main units of
chromatin organization. Chromatin exist in two states - either as eu- or heterochromatin,
which either promotes or silences gene expression as a consequence of its
packing states. Eukaryotic cells have developed epigenetic regulation to control the
chromatin state, and to guarantee a high level of differentiation.
The basis of epigenetic regulation are patterns of post-translational modifications
of the nucleosomal proteins. These modifications are performed by epigenetic
enzymes. This thesis focuses on one of these enzymes - the human lysine methyltransferase
SMYD3. SMYD3 is also capable of interacting with certain cytosolic
proteins, such as the molecular chaperone HSP90 - the human Heat Shock Protein
90. Both proteins are of high interest in the drug research and development landscape,
as a drastic change in their activity and expression levels have both been
shown to be related to several cancers or neurodevelopmental diseases.
In this work, various truncated forms of HSP90 were produced and probed for
their interactions with SMYD3 using surface plasmon resonance-based biosensor
technology. A previously reported interaction of SMYD3 with the C-terminal domain
of HSP90 was confirmed, with an affinity discovered to be KD = 1.3 × 10−5M.
Additionally, the biosensor-based assay was used to test potential ligands of SMYD3,
including low affinity fragment-like organic molecules. To complement the study,
extensive crystallization and co-crystallization trials were carried out with SMYD3.
As a result, conditions for the formation of various crystal forms of SMYD3 were
mapped, with the best crystal form found to have high stability and good diffraction
properties.
A set of experiments presented herein develops expertise in the tools one can use
for an efficient and rational ligand discovery campaign targeting SMYD3 histone
methyltransferase.
Beskrivning
Ämne/nyckelord
SMYD3 , HSP90 , SPR , XRD , MST , TSA , drug discovery