Biomaterial Database

Crystalline cylindrical structures of Na(+)-bound dimyristoylphosphatidylglycerol as revealed by microcalorimetry and electron microscopy. 1993

M Kodama, and T Miyata, and T Yokoyama

Department of Biochemistry, Faculty of Science, Okayama University of Science, Japan.

Multilamellar vesicles of dimyristoylphosphatidylglycerol (DMPG) in an aqueous medium of 1 M NaCl at pH 7.0 converted to defined cylindrical structures of crystalline phase, on annealing of 5 degrees C of a gel phase temperature. The new crystalline phase transformed into the liquid crystal phase at a transition point (44.2 degrees C) nearly the same as that of the protonated DMPG, but with a transition enthalpy (19.2 kcal/mol) larger than that of the Ca(2+)-bound DMPG of much higher transition temperature. Electron microscopic observations revealed that a set of outer membranes (8-10 lamellae) separated from the MLV grows into helical structures and, finally, into the crystalline cylindrical structures with an increase in annealing time.

UI	MeSH Term	Description	Entries
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D010715	Phosphatidylglycerols	A nitrogen-free class of lipids present in animal and particularly plant tissues and composed of one mole of glycerol and 1 or 2 moles of phosphatidic acid. Members of this group differ from one another in the nature of the fatty acids released on hydrolysis.	Glycerol Phosphoglycerides,Monophosphatidylglycerols,Phosphatidylglycerol,Phosphatidyl Glycerol,Glycerol, Phosphatidyl,Phosphoglycerides, Glycerol
D002151	Calorimetry	The measurement of the quantity of heat involved in various processes, such as chemical reactions, changes of state, and formations of solutions, or in the determination of the heat capacities of substances. The fundamental unit of measurement is the joule or the calorie (4.184 joules). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
D003461	Crystallography	The branch of science that deals with the geometric description of crystals and their internal arrangement. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Crystallographies
D012965	Sodium Chloride	A ubiquitous sodium salt that is commonly used to season food.	Sodium Chloride, (22)Na,Sodium Chloride, (24)NaCl
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures
D013816	Thermodynamics	A rigorously mathematical analysis of energy relationships (heat, work, temperature, and equilibrium). It describes systems whose states are determined by thermal parameters, such as temperature, in addition to mechanical and electromagnetic parameters. (From Hawley's Condensed Chemical Dictionary, 12th ed)	Thermodynamic