TY - JOUR AB - Biological membranes constantly modulate their fluidity for proper functioning of the cell. Modulation of membrane properties via regulation of fatty acid composition has gained a renewed interest owing to its relevance in endocytosis, endoplasmic reticulum membrane homeostasis, and adaptation mechanisms in the deep sea. Endowed with significant degrees of freedom, the presence of free fatty acids can alter the curvature of membranes which in turn can alter the response of curvature sensing proteins, thus defining adaptive ways to reconfigure membranes. Most significantly, recent experiments demonstrated that polyunsaturated lipids facilitate membrane bending and fission by endocytic proteins – the first step in the biogenesis of synaptic vesicles. Despite the vital roles of fatty acids, a systematic study relating the interactions between fatty acids and membrane and the consequent effect on the bio-mechanics of membranes under the influence of fatty acids has been sparse. Of specific interest is the vast disparity in the properties of cis and trans fatty acids, that only differ in the orientation of the double bond and yet have entirely unique and opposing chemical properties. Here we demonstrate a combined X-ray diffraction and membrane fluctuation analysis method to couple the structural properties to the biophysical properties of fatty acid-laden membranes to address current gaps in our understanding. By systematically doping pure dioleoyl phosphatidylcholine (DOPC) membranes with cis fatty acid and trans fatty acid we demonstrate that the presence of fatty acids doesn’t always fluidize the membrane. Rather, an intricate balance between the curvature, molecular interactions, as well as the amount of specific fatty acid dictates the fluidity of membranes. Lower concentrations are dominated by the nature of interactions between the phospholipid and the fatty acids. Trans fatty acid increases the rigidity while decreasing the area per lipid similar to AU - Tyler,AII AU - Greenfield,JL AU - Seddon,JM AU - Brooks,NJ AU - Purushothaman,S DO - 10.3389/fcell.2019.00187 PY - 2019/// SN - 2296-634X TI - Coupling phase behavior of fatty acid containing membranes to membrane bio-mechanics T2 - Frontiers in Cell and Developmental Biology UR - http://dx.doi.org/10.3389/fcell.2019.00187 UR - https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000486682900001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=a2bf6146997ec60c407a63945d4e92bb UR - https://www.frontiersin.org/articles/10.3389/fcell.2019.00187/full UR - http://hdl.handle.net/10044/1/108135 VL - 7 ER -