Steroidal triterpenes of cholesterol synthesis

Jure Ačimovič (Author), Damjana Rozman (Author)

Abstract

Cholesterol synthesis is a ubiquitous and housekeeping metabolic pathway that leads to cholesterol, an essential structural component of mammalian cell membranes, required for proper membrane permeability and fluidity. The last part of the pathway involves steroidal triterpenes with cholestane ring structures. It starts by conversion of acyclic squalene into lanosterol, the first sterol intermediate of the pathway, followed by production of 20 structurally very similar steroidal triterpene molecules in over 11 complex enzyme reactions. Due to the structural similarities of sterol intermediates and the broad substrate specificity of the enzymes involved (especially sterol-Ä24-reductase; DHCR24) the exact sequence of the reactions between lanosterol and cholesterol remains undefined. This article reviews all hitherto known structures of post-squalene steroidal triterpenes of cholesterol synthesis, their biological roles and the enzymes responsible for their synthesis. Furthermore, it summarises kinetic parameters of enzymes (Vmax and Km) and sterol intermediate concentrations from various tissues. Due to the complexity of the post-squalene cholesterol synthesis pathway, future studies will require a comprehensive meta-analysis of the pathway to elucidate the exact reaction sequence in different tissues, physiological or disease conditions. A major reason for the standstill of detailed late cholesterol synthesis research was the lack of several steroidal triterpene standards. We aid to this efforts by summarizing commercial and laboratory standards, referring also to chemical syntheses of meiosisactivating sterols.

Keywords

sterols;steroidal triterpenes;cholesterol synthesis;

Data

Language:	English
Year of publishing:	2013
Typology:	1.02 - Review Article
Organization:	UL MF - Faculty of Medicine
UDC:	577
COBISS:	30538457
ISSN:	1420-3049
Views:	199
Downloads:	66
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	Slovenian
Secondary keywords:	steroli;steroidne triterpeni;cholesterol synthesis;
Type (COBISS):	Article
Pages:	str. 4002-4017
Volume:	ǂVol. ǂ18
Issue:	ǂno. ǂ4
Chronology:	2013
DOI:	10.3390/molecules18044002
ID:	13307413