Biomaterial Database

Effects of temperature and lipid composition on the serum albumin-induced aggregation and fusion of small unilamellar vesicles. 1981

S Schenkman, and P S Araujo, and R Dijkman, and F H Quina, and H Chaimovich

Small unilamellar vesicles of egg phosphatidylcholine (PC) or dimyristoylphosphatidylcholine, mixed with small unilamellar vesicles labelled with 2-(10-(1-pyrene)decanoyl)phosphatidylcholine, exhibit a constant average size and excimer to monomer (E/M) ratio for several hours when incubated at pH 3.6 at a temperature higher than the phase transition temperature (Tc) of the lipids. Addition of bovine serum albumin to this system produces a transient turbidity increase, a fast decrease in the E/M ratio, a partial loss of vesicle-entrapped [14C]sucrose and a measurable leak-in of externally added sucrose. Sepharose 4B filtration of the system demonstrates that the E/M ratio decrease is strictly paralleled by the formation of liposomes which exhibit a low E/M ratio and a hydrodynamic radius larger than that of small unilamellar vesicles. These data demonstrate that the E/M ratio decrease can be unequivocally ascribed to a vesicle-vesicle fusion process induced by serum albumin. The rate of serum-albumin induced fusion of small unilamellar vesicles is: (a) maximal at a stoichiometric ratio of approx. 2 albumins per vesicle; (b) sensitive to the nature of the lipid and; (c) not altered when human serum albumin replaces bovine serum albumin. The rate of albumin-induced fusion of dimyristoylphosphatidylcholine small unilamellar vesicles is higher below the Tc of the lipid and increases with temperature above the Tc. The formation of protein-bound aggregates with defined stoichiometries and a high local vesicle concentration, as well as changes in the local degree of hydration, are proposed to be the driving forces for the protein-induced vesicle fusion in this system.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008081	Liposomes	Artificial, single or multilaminar vesicles (made from lecithins or other lipids) that are used for the delivery of a variety of biological molecules or molecular complexes to cells, for example, drug delivery and gene transfer. They are also used to study membranes and membrane proteins.	Niosomes,Transferosomes,Ultradeformable Liposomes,Liposomes, Ultra-deformable,Liposome,Liposome, Ultra-deformable,Liposome, Ultradeformable,Liposomes, Ultra deformable,Liposomes, Ultradeformable,Niosome,Transferosome,Ultra-deformable Liposome,Ultra-deformable Liposomes,Ultradeformable Liposome
D008246	Lysophospholipids	Derivatives of PHOSPHATIDIC ACIDS that lack one of its fatty acyl chains due to its hydrolytic removal.	Lysophosphatidic Acids,Lysophospholipid,Acids, Lysophosphatidic
D010713	Phosphatidylcholines	Derivatives of PHOSPHATIDIC ACIDS in which the phosphoric acid is bound in ester linkage to a CHOLINE moiety.	Choline Phosphoglycerides,Choline Glycerophospholipids,Phosphatidyl Choline,Phosphatidyl Cholines,Phosphatidylcholine,Choline, Phosphatidyl,Cholines, Phosphatidyl,Glycerophospholipids, Choline,Phosphoglycerides, Choline
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D004134	Dimyristoylphosphatidylcholine	A synthetic phospholipid used in liposomes and lipid bilayers for the study of biological membranes.	Dimyristoyllecithin,1,2-Dimyristoyl-glycero-3-phosphorylcholine,1,2-Ditetradecanoyl-glycero-3-phosphocholine,1,2-Ditetradecyl-glycero-3-phosphocholine,DMCP,DMPC,1,2 Dimyristoyl glycero 3 phosphorylcholine,1,2 Ditetradecanoyl glycero 3 phosphocholine,1,2 Ditetradecyl glycero 3 phosphocholine
D005456	Fluorescent Dyes	Chemicals that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.	Flourescent Agent,Fluorescent Dye,Fluorescent Probe,Fluorescent Probes,Fluorochrome,Fluorochromes,Fluorogenic Substrates,Fluorescence Agents,Fluorescent Agents,Fluorogenic Substrate,Agents, Fluorescence,Agents, Fluorescent,Dyes, Fluorescent,Probes, Fluorescent,Substrates, Fluorogenic
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012710	Serum Albumin, Bovine	Serum albumin from cows, commonly used in in vitro biological studies. (From Stedman, 25th ed)	Fetal Bovine Serum,Fetal Calf Serum,Albumin Bovine,Bovine Albumin,Bovine Serum Albumin,Albumin, Bovine,Albumin, Bovine Serum,Bovine Serum, Fetal,Bovine, Albumin,Calf Serum, Fetal,Serum, Fetal Bovine,Serum, Fetal Calf
D013053	Spectrophotometry	The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.