An Upside Down View of Cholesterol's Condensing Effect: Does Surface Occupancy Play a Role?

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Janout V., Turkyilmaz S., Wang M., Wang Y., Manaka Y., Regen S. L.

LANGMUIR, cilt.26, sa.8, ss.5316-5318, 2010 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 26 Sayı: 8
  • Basım Tarihi: 2010
  • Doi Numarası: 10.1021/la100878s
  • Dergi Adı: LANGMUIR
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.5316-5318
  • Orta Doğu Teknik Üniversitesi Adresli: Hayır

Özet

The condensing action or cholesterol has been compared with that of a structural isomer having its hydroxyl group located at the C-25 position (i.e., 25-OH'), that is, an isomer favoring an "upside down" orientation in lipid membranes. Surface pressure area isotherms of mixed monolayers made from 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DM PC)/cholesterol and DM PC/25-OH' have established that 25-OH' has a weaker condensing effect than cholesterol. Nearest-neighbor recognition measurements in liposomes made from 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) have also shown that 25-OH' has a weaker condensing effect in the physiologically relevant fluid bilayer state. These findings provide support for surface occupancy playing a role in the condensing action of cholesterol.