Inhibition of human 3-hydroxy-3-methylglutaryl CoA reductase by peptides leading to cholesterol homeostasis through SREBP2 pathway in HepG2 cells.

Varun, Kumar and Sharma, P. and Bairagya, H. R. and Sharma, S. and Singh, T. P. and Purnima Kaul, Tiku (2019) Inhibition of human 3-hydroxy-3-methylglutaryl CoA reductase by peptides leading to cholesterol homeostasis through SREBP2 pathway in HepG2 cells. BBA - Proteins and Proteomics, 1867. pp. 604-615.

PDF BBA - Proteins and Proteomics 1867 (2019) 604–615.pdf - Published Version Restricted to Registered users only Download (1MB) | Request a copy

Abstract

In mammalian cells, human 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), a rate-limiting endoplasmic reticulum (ER) bonded enzyme, plays a central role in the cholesterol homeostasis via the negative feedback mechanism. The present study indicates that the interactions of novel peptides with the catalytic domain of HMGCR, provides an alternative therapeutic candidate for reducing cholesterol. The potential natural origin of HMGCR peptide inhibitors were filtered from the peptide library using the molecular docking, which revealed three strong candidates for inhibition. This information was used for synthesizing peptides, which were evaluated for inhibition against HMGCR. The stronger docking interactions were confirmed by experimental dissociation constant (KD) values of 9.1×10−9 M, 1.4×10−8M and 1.2×10−8M for peptides NALEPDNRIESEGG (Pep-1), NALEPDNRIES (Pep-2) and PFVKSEPIPETNNE (Pep-3) respectively. The immunological based interactions show a strong evidence of peptide-HMGCR complexes. The LDL uptake showed enhancements after treatments with peptides in the extracellular environment of HepG2 cells, which was further, corroborated through increase in the immunofluorescence signal of the localized LDL-R protein expression on the cell membrane. The results showed that the mRNA and protein expression of transcription factors were significantly up-regulated showing regulation of cholesterol biosynthesis in peptide treated HepG2 cells. The binding of transcription factors, sterol regulatory element (SRE) and cAMP-response element (CRE) on HMGCR promotor further confirms the cholesterol biosynthesis regulation. All the above results suggested a key role of peptide/s in alleviating cholesterol accumulation in tissue via inhibition of rate-limiting HMGCR enzyme.

Item Type:	Article
Uncontrolled Keywords:	SRE CRE HMGCR LDL-R cholesterol accumulation HepG2 cells
Subjects:	500 Natural Sciences and Mathematics > 04 Chemistry and Allied Sciences > 25 Peptide Chemistry
Divisions:	Protein Chemistry and Technology
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	15 May 2019 06:36
Last Modified:	15 May 2019 06:36
URI:	http://ir.cftri.res.in/id/eprint/13964

Actions (login required)

View Item