CaltechAUTHORS
  A Caltech Library Service

Stereochemical engineering of a peptide macrocycle allosteric inhibitor of phospho-Akt2 controls cell penetration by fine-tuning macrocycle-cell membrane interactions

Nag, Arundhati and Mafi, Amirhossein and Das, Samir and Yu, Mary Beth and Alvarez-Villalonga, Belen and Goddard, William A., III and Heath, James R. (2021) Stereochemical engineering of a peptide macrocycle allosteric inhibitor of phospho-Akt2 controls cell penetration by fine-tuning macrocycle-cell membrane interactions. . (Unpublished) https://resolver.caltech.edu/CaltechAUTHORS:20211209-231124000

[img] PDF - Submitted Version
Creative Commons Attribution Non-commercial No Derivatives.

6MB
[img] PDF - Supplemental Material
Creative Commons Attribution Non-commercial No Derivatives.

15MB

Use this Persistent URL to link to this item: https://resolver.caltech.edu/CaltechAUTHORS:20211209-231124000

Abstract

We report the development of a cell-penetrant cyclic loop biligand that selectively binds, in vitro, to the phosphorylated Ser474 site of Protein Kinase B (p-Akt2) with high affinity (K_D = 10 nM). The cyclic loop biligand consists of a linear peptide joined to a macrocycle peptide through triazole linkage, and it was isolated through two iterative in situ screens. This biligand allosterically inhibited kinase activity of Akt2 but it was cell-impermeable, as isolated from the screening process. Since Akt2 is an oncoprotein hyperactivated via phosphorylation at Ser474 in cancers, we sought to visualize p-Akt2 in live cancer cells using the developed biligand. To this end, we matured this biligand into a cell-penetrant reagent through systematic iterations of its chemical structure to promote cell-penetrating properties, while retaining its binding and inhibition for p-Akt2. Two retro-inverso, N-methylated versions of the macrocyclic ligand were developed which were uptaken by live cancer cells, while retaining their high affinities for pAkt2. Interestingly, the stereochemistry of two amino acid residues in the cell-penetrant ligands exhibited strong influence on their extent of cell penetration. This phenomenon of difference in cell penetration was explored through metadynamics simulations of each ligand in the cell membrane. It was found that the ligand uptaken to a greater extent by cells had more intramolecular interactions with itself and had fewer cholesterol molecules associated with it, which aided in its cell-penetration.


Item Type:Report or Paper (Discussion Paper)
Related URLs:
URLURL TypeDescription
https://doi.org/10.26434/chemrxiv-2021-kldh7DOIDiscussion Paper
ORCID:
AuthorORCID
Nag, Arundhati0000-0002-1328-1695
Mafi, Amirhossein0000-0002-8366-6785
Goddard, William A., III0000-0003-0097-5716
Heath, James R.0000-0001-5356-4385
Additional Information:The content is available under CC BY NC ND 4.0 License. The various PCCs reported here were developed under funding from the National Cancer Institute through grant #1U54 CA199090-01 (JRH PI). WAG and AM thank NIH (NIH R35HL150807) for support. Author’s competing interest statement. James R Heath is a founder and board member of Indi Molecular, which is a company seeking to commercialize PCC technology. The author(s) declare that they have sought and gained approval from the relevant ethics committee/IRB for this research and its publication.
Funders:
Funding AgencyGrant Number
NIH1U54 CA199090-01
NIHR35HL150807
DOI:10.26434/chemrxiv-2021-kldh7
Record Number:CaltechAUTHORS:20211209-231124000
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20211209-231124000
Official Citation:Nag A, Mafi A, Das S, et al. Stereochemical engineering of a peptide macrocycle allosteric inhibitor of phospho-Akt2 controls cell penetration by fine-tuning macrocycle-cell membrane interactions. ChemRxiv. 2021. doi:10.26434/chemrxiv-2021-kldh7
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:112349
Collection:CaltechAUTHORS
Deposited By: George Porter
Deposited On:10 Dec 2021 20:26
Last Modified:01 Feb 2022 22:54

Repository Staff Only: item control page