Potential Pharmacological Chaperones

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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 2 nd Year

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

Molecular Chaperones

Molecular Cell Biology, 6th Edition W.H. Freeman & Company

Pharmacological Chaperones (PC)

Structural genomics consortium (www.sgc.org)

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

Design of Triazine-Piperazine-Triazine scaffold as α-Helix

Mimetic

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

General strategy for identification of α-helix mimetics that bind to the target protein

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.

Structure of MCL-1 binding hit-compounds

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

General strategy for identification of α-helix mimetics that bind to the target protein

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.