Biomaterial Database

Effect of calcium ion on the mechanical properties of lipid bilayer membrane. 1982

S Mitaku, and S Aruga

Elastic properties of dipalmitoyl phosphatidylcholine bilayers were studied by an ultrasonic technique as a function of the concentration of calcium ion. The ultrasonic velocity showed a broad minimum at about 10 mM CaCl2, indicating that the bulk modulus of membrane is smallest at this calcium ion concentration. Since the amount of calcium ions adsorbed to the membrane monotonously increases, calcium ions have two kinds of effects on the phosphatidylcholine membrane, namely softening effect at lower concentration and hardening at higher concentration. It is suggested that the softening is due to some structural change of hydrated water and the hardening is due to chelation of lipid molecules by adsorbed calcium ions. The estimation of bulk modulus and Young's modulus revealed that Young's modulus and rigidity are much smaller than the bulk modulus even in the gel phase.

UI	MeSH Term	Description	Entries
D007473	Ion Channels	Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.	Membrane Channels,Ion Channel,Ionic Channel,Ionic Channels,Membrane Channel,Channel, Ion,Channel, Ionic,Channel, Membrane,Channels, Ion,Channels, Ionic,Channels, Membrane
D008051	Lipid Bilayers	Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.	Bilayers, Lipid,Bilayer, Lipid,Lipid Bilayer
D011663	Pulmonary Surfactants	Substances and drugs that lower the SURFACE TENSION of the mucoid layer lining the PULMONARY ALVEOLI.	Surfactants, Pulmonary,Pulmonary Surfactant,Surfactant, Pulmonary
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002463	Cell Membrane Permeability	A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.	Permeability, Cell Membrane
D004548	Elasticity	Resistance and recovery from distortion of shape.
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D013314	Stress, Mechanical	A purely physical condition which exists within any material because of strain or deformation by external forces or by non-uniform thermal expansion; expressed quantitatively in units of force per unit area.	Mechanical Stress,Mechanical Stresses,Stresses, Mechanical
D014465	Ultrasonics	A subfield of acoustics dealing in the radio frequency range higher than acoustic SOUND waves (approximately above 20 kilohertz). Ultrasonic radiation is used therapeutically (DIATHERMY and ULTRASONIC THERAPY) to generate HEAT and to selectively destroy tissues. It is also used in diagnostics, for example, ULTRASONOGRAPHY; ECHOENCEPHALOGRAPHY; and ECHOCARDIOGRAPHY, to visually display echoes received from irradiated tissues.	Ultrasonic