Plant sterol and stanol substrate specificity of pancreatic cholesterol esterase

Andrew W. Brown, Jiliang Hang, Patrick H. Dussault, Timothy P. Carr

Research output: Contribution to journalArticlepeer-review

28 Scopus citations

Abstract

Consumption of plant sterols or stanols (collectively referred to as phytosterols) and their esters results in decreased low-density lipoprotein cholesterol, which is associated with decreased atherosclerotic risk. The mechanisms by which phytosterols impart their effects, however, are incompletely characterized. The objective of the present study is to determine if pancreatic cholesterol esterase (PCE; EC 3.1.1.13), the enzyme primarily responsible for cholesterol ester hydrolysis in the digestive tract, is capable of hydrolyzing various phytosterol esters and to compare the rates of sterol ester hydrolysis in vitro. We found that PCE hydrolyzes palmitate, oleate and stearate esters of cholesterol, stigmasterol, stigmastanol and sitosterol. Furthermore, we found that the rate of hydrolysis was dependent on both the sterol and the fatty acid moieties in the following order of rates of hydrolysis: cholesterol>(sitosterol=stigmastanol)>stigmasterol; oleate>(palmitate=stearate). The addition of free phytosterols to the system did not change hydrolytic activity of PCE, while addition of palmitate, oleate or stearate increased activity. Thus, PCE may play an important but discriminatory role in vivo in the liberation of free phytosterols to compete with cholesterol for micellar solubilization and absorption.

Original languageEnglish (US)
Pages (from-to)736-740
Number of pages5
JournalJournal of Nutritional Biochemistry
Volume21
Issue number8
DOIs
StatePublished - Aug 2010

Keywords

  • Cholesterol absorption
  • Cholesterol metabolism
  • Lipase
  • Phytosterols
  • Plant stanols
  • Plant sterols

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Biochemistry
  • Molecular Biology
  • Nutrition and Dietetics
  • Clinical Biochemistry

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