Identification of small molecules by screening a mixture-based scaffold compound library for treatment of alpha-1 antitrypsin deficiency

Authors

Xiaojuan Zhang, University of Florida College of Medicine
Radleigh Santos, Torrey Pines Institute for Molecular Studies; Nova Southeastern UniversityFollow
Ginamarie Debevec, Torrey Pines Institute for Molecular Studies
Danmeng Li, University of Florida College of Medicine
Ryan Schutte, University of Florida College of Medicine
Kien Pham, Rutgers, The State University of New Jersey
Chen Liu, Rutgers, The State University of New Jersey
David A. Ostrov, University of Florida College of Medicine
Marc Giulianotti, Torrey Pines Institute for Molecular Studies

Document Type

Article

Publication Date

6-18-2020

Publication Title

Biochemical and Biophysical Research Communications

Keywords

Alpha-1 antitrypsin Liver disease Drug discovery Mixture-based libraries

ISSN

0006-291X

Volume

527

Issue/No.

1

First Page

317

Last Page

323

Abstract

This study aimed to identify small molecules that have the potential to treat alpha1-antitrypsin deficiency (AATD) by screening compounds available from a mixture-based scaffold library. 93 scaffold libraries (total diversity of >30 million compounds in mixture format) were screened using a cell model of AATD in order to identify samples that could either reduce intracellular aggregation of Z-form AAT protein, increase extracellular secretion of Z-AAT or both. Mixture libraries containing compounds with in vitro activity, for example library 1295, were screened further to identify individual active compounds. The mixture format of the scaffold library allowed for some preliminary structure-activity relationships to be developed and also enabled the rapid selection of a promising scaffold. Utilizing this scaffold, 1295, a collection of individual “control” compounds contained in the 1295 mixture sample were then screened. A sub-library of individual “control” compounds featuring structural diversity at position R1 (1295.R1), was screened and 7 compounds were found to reduce the intracellular accumulation of Z-AAT without affecting cell viability at a concentration of 25ug/ml (about 50 μM). Screening sub-libraries featuring structural diversity at R2 and R3 (1295.R2 and 1295.R3) identified an additional 15 active compounds. Titration experiments identified 3 compounds from the 1295.R2 library that retained activity at 5ug/ml (approx. 10uM). One compound (1295.263) from 1295.R2 decreased intracellular levels of Z-AAT without affecting cell viability and wild-type AAT levels at the concentration of 5ug/ml. Molecular docking of this compound to the Z-AAT crystal structure identified a potential binding site near the C-terminal domain, an identified polymerization site. Our results indicate that screening large mixture-based compound libraries can be used to identify small molecules that may have the potential to treat AATD and other disease.

Comments

This work was supported by an Experimental Pathology Innovative Grant from the Department of Pathology, Immunology, and Laboratory Medicine, University of Florida to Zhang XJ; James and Esther King Biomedical Research Program [grant number JK05], Florida Department of Health, Florida, United States to Ostrov DA; and State of Florida, Executive Office of the Governor’s Office of Tourism, Trade, and Economic Development (for TPI).

NSUWorks Citation

Zhang, Xiaojuan; Santos, Radleigh; Debevec, Ginamarie; Li, Danmeng; Schutte, Ryan; Pham, Kien; Liu, Chen; Ostrov, David A.; and Giulianotti, Marc, "Identification of small molecules by screening a mixture-based scaffold compound library for treatment of alpha-1 antitrypsin deficiency" (2020). Mathematics Faculty Articles. 305.
https://nsuworks.nova.edu/math_facarticles/305

DOI

10.1016/j.bbrc.2020.04.037