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

Janout, Vaclav
Türkyılmaz, Serhan
Wang, Minghui
Wang, Yao
Manaka, Yuichi
Regen, Steven L.
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.


The Effect of 15-lipoxygenase-1 (15-LOX-1) on angiogenesis in colorectal and prostate cancer
Çolakoğlu, Melis; Banerjee, Sreeparna; Department of Biology (2017)
15-lipoxygenase-1 (15-LOX-1) is one of the lipoxygenases (LOX) that are important for the generation of inflammatory bioactive lipids, which then result in the initiation and resolution of inflammation. The enzyme mainly metabolizes the omega-6 fatty acid, linoleic acid, to 13-(S)-HODE. In colorectal carcinoma, the tumor suppressive role of 15-LOX-1 is highlighted with decreased proliferation, induction of apoptosis, reduced motility and invasion. Oppositely, the expression of 15-LOX-1 was reported to have ...
Emerging cellular functions of the lipid metabolizing enzyme 15-Lipoxygenase-1
Colakoglu, Melis; Tuncer, Sinem; Banerjee, Sreeparna (Wiley, 2018-10-01)
The oxygenation of polyunsaturated fatty acids such as arachidonic and linoleic acid through lipoxygenases (LOXs) and cyclooxygenases (COXs) leads to the production of bioactive lipids that are important both in the induction of acute inflammation and its resolution. Amongst the several isoforms of LOX that are expressed in mammals, 15-LOX-1 was shown to be important both in the context of inflammation, being expressed in cells of the immune system, and in epithelial cells where the enzyme has been shown to...
The effect of indole acetic acid, abscisic acid, gibberellin and kinetin on the expression of arf1 gtp binding protein of pea (pisum sativum l. cv. araka)
Ertekin, Özlem; Memon, Abdulrezzak; Department of Biology (2007)
ADP Ribosylation Factor 1 (ARF1) is a universal small GTP binding protein which has an important role in vesicular trafficking between endoplasmic reticulum and Golgi. ARF1 is a basic component of Coat Protein I (COPI) vesicles which have functions in both formation of coatomer complex and recruitment of cargo proteins. In this study, the expression ARF1 was analyzed in pea (P. sativum L. cv. Araka) grown at different developmental stages. Because of the differential hormonal levels at corresponding stages,...
Evaluation of an aldo-keto reductase gene signature with prognostic significance in colon cancer via activation of epithelial to mesenchymal transition and the p70S6K pathway
Canli, Secil Demirkol; Seza, Esin Gulce; Sheraj, Ilir; Gomceli, Ismail; Turhan, Nesrin; Carberry, Steven; Prehn, Jochen H. M.; GÜRE, ALİ OSMAY; Banerjee, Sreeparna (Oxford University Press (OUP), 2020-09-01)
AKR1B1 and AKR1B10, members of the aldo-keto reductase family of enzymes that participate in the polyol pathway of aldehyde metabolism, are aberrantly expressed in colon cancer. We previously showed that high expression of AKR1B1 (AKR1B1(HIGH)) was associated with enhanced motility, inflammation and poor clinical outcome in colon cancer patients. Using publicly available datasets and ex vivo gene expression analysis (n = 51, Ankara cohort), we have validated our previous in silico finding that AKR1B1(HIGH) ...
Investigation of the cellular mechanisims underlying the Carboxypeptidase E mutation
Kaşıkçı, Feride; Yanık, Tülin; Department of Biology (2014)
Carboxypeptidase E (CPE) is an enzyme expressed in both endocrine and neuroendocrine cells functioning as both an exopeptidase and a sorting receptor. Recently, it has been reported that CPE plays a role in preventing neuronal cell death in the CA3 hippocampus so as to maintain normal cognitive function in the adult brain. Studies on CPE-knockout mice showed total degeneration of neurons in the CA3 region of the hippocampus in adult mice 4 weeks of age and older. Additionally, increased CPE expression was i...
Citation Formats
V. Janout, S. Türkyılmaz, M. Wang, Y. Wang, Y. Manaka, and S. L. Regen, “An Upside Down View of Cholesterol’s Condensing Effect: Does Surface Occupancy Play a Role?,” LANGMUIR, pp. 5316–5318, 2010, Accessed: 00, 2020. [Online]. Available: