Helicobacter pylori lipids can form ordered membrane domains (rafts)

Publication date: Available online 23 August 2019Source: Biochimica et Biophysica Acta (BBA) - BiomembranesAuthor(s): Zhen Huang, Xue-Song Zhang, Martin J. Blaser, Erwin LondonAbstractOrdered lipid domains (rafts) are generally considered to be features of eukaryotic cells, but ordered lipid domains formed by cholesterol lipids have been identified in bacteria from the genus Borrelia, and similar cholesterol lipids exist in the bacterium Helicobacter pylori. To determine whether H. pylori lipids could form ordered membrane domains, we investigated domain formation in aqueous dispersions of H. pylori whole lipid extracts, individual H. pylori lipids, or defined mixtures of H. pylori lipids, or other membrane-forming lipids. DPH (1,6-diphenyl-1,3,5-hexatriene) anisotropy measurements were used to assay membrane order and FRET (Förster resonance energy transfer) was used to detect the presence of co-existing ordered and disordered domains. We found that H. pylori membrane lipid extracts spontaneously formed lipid domains. Domain formation was more stable when lipids were extracted from H. pylori cells grown in the presence of cholesterol. Certain isolated H. pylori lipids (by themselves or when mixed with other lipids) also had the ability to form ordered domains. To be specific, H. pylori cholesteryl-6-O-tetradecanoyl-α-D-glucopyranoside (CAG) and cholesterol-6-O-phosphatidyl-α-D-glucopyranoside (CG) had the ability to form and/or stabilize ordered domain formation, while H....
Source: Biochimica et Biophysica Acta (BBA) Biomembranes - Category: Biochemistry Source Type: research