Potential Pharmacological Chaperones
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Transcript of Potential Pharmacological Chaperones
Potential Pharmacological Chaperones Targeting Cancer-
Associated MCL-1 And Parkinson Disease-Associated α-Synuclein
Misook Oh, et. al.,Proc. Natl. Acad. Sci. U.S.A (2014) 111:11007-11012
Presented by:Rajni
Msc 2nd Year
Enzymes inhibitors v/s Pharmacological chaperones as
drugs (PC)
Most drugs are enzymes inhibitors.These drugs compete with the natural substrates for binding
with the target protein.e.g. Amprenavir-is a protease inhibitor which is used to
treat HIV infection.PC are bind to the protein and stabilize them against thermal
denaturation, aggregation, and prevent certain protein-protein interaction.
Effective PC are-cofactor mimetics,ligand mimetics,secondary structure mimetics bind to target protein and stabilized them.
Challenges in Discovering PCDiscovering Pharmacological chaperones for specific target is
challenging because –
1. featureless target protein surface 2. lack of suitable chemical libraries 3. shortage of efficient High-Throughput-Screening methods
In this study, authors have addressed all these challenges and discovered a potential pharmacological chaperones against-
1. Cancer-associated , myeloid cell leukemia1(MCL-1) protein 2. Parkinson disease-associated,α-synuclein protein
Cellpress , www.cell.com
MCL-1 interaction with proapoptotic proteins (BAK)
leads to cancer
[e.g. BAK]
α-Synuclein misfolding and aggregation is associated with
Parkinsons
Irwin et. al., Nat. Rev. Neurosci. (2013)
Outline
Design of an scaffold as α-helix mimetics
Construction of a peptoid-encoded one-bead-one-compound (OBOC) combinatorial library of α-helix mimetics
High throughput screening (HTS) against MCL-1 protein and α-synuclein
MCL-1 binding assay and cellular assays
α-synuclein binding and aggregation assay
Outline
Design of an scaffold as α-helix mimetics
Construction of a peptoid-encoded one-bead-one-compound (OBOC) combinatorial library of α-helix mimetics
High throughput screening (HTS) against MCL-1 protein and α-synuclein
MCL-1 binding assay and cellular assays
α-synuclein binding and aggregation assay
Outline
Design of an scaffold as α-helix mimetics
Construction of a peptoid-encoded one-bead-one-compound (OBOC) combinatorial library of α-helix mimetics
High throughput screening (HTS) against MCL-1 protein and α-synuclein
MCL-1 binding assay and cellular assays
α-synuclein binding and aggregation assay
Advantages of using peptoid-encoded OBOC library
Large number of library molecules can be screened simultaneously in single tube
Peptide encoding helps in identification of hit compound
Many proteins alter surface upon binding of partner and create new binding pockets
The dynamic pockets can also be identified using this unbiased OBOC library.
Outline
Design of an scaffold as α-helix mimetics
Construction of a peptoid-encoded one-bead-one-compound (OBOC) combinatorial library of α-helix mimetics
High throughput screening (HTS) against MCL-1 protein and α-synuclein
MCL-1 binding assay and cellular assays
α-synuclein binding and aggregation assay
Binding assay of hit compounds to MCL-1
9c has highest binding affinity for MCL-1 and can antagonize the interaction between MCL-1 and BH3 (domain of BAK)
9c selectively binds to MCL-1
BCL-XL (member of BCL-2 family) gets inhibited by BH3 peptide, but not by 9c
Predicted binding mode of 9c
Computer docking predicts that BH3 and 9c, both binds in the hydrophobic groove of MCL-1
BH3-peptide 9c compound
MCL-1 Cellular assay
9c is cell permeable and competitively bind to MCL-1 therefore liberating BAK protein and confirmed the cellular uptake of 9c
by using confocal microscopy
Effect of 9c on cell viability
Jurkat T-leukemia cells normal fibroblast cells
9c has selective toxicity to malignant cell with MCL-1 overexpression over normal cells
Outline
Design of an scaffold as α-helix mimetics
Construction of a peptoid-encoded one-bead-one-compound (OBOC) combinatorial library of α-helix mimetics
High throughput screening (HTS) against MCL-1 protein and α-synuclein
MCL-1 binding assay and cellular assays
α-synuclein binding and aggregation assay
Binding assay of α-Synuclein
Q1 has highest binding affinity for WT α-synuclein and increase their thermal stability
Aggregation assay of α-Synuclein
Q compounds having strong binding to mutant-type α-synuclein and also delayed the α-synuclein aggregation
Summary Designed novel α-Helix Mimetics (Triazine-Piperazine-
Triazine) scaffold. Constructed OBOC library of this α-Helix Mimetics by using
different building blocks. Designed novel High-Throughput-Screening of OBOC library
of α-Helix Mimetics to identify compounds against cancer associated-MCL-1 and parkinson-associated α-Synuclein. Binding assays with MCL-1 shows that PC can prevent MCL-1 interaction with natural binding partner BAK.
Binding assays with α-Synuclein shows that PC can enhance its stability and prevent aggregation.
Present work is proof-of-concept that pharmacological chaperones can be important in diseases involving protein-protein interaction.