Biomaterial Database

The relationship between phospholipid content and Ca2+-ATPase activity in the sarcoplasmic reticulum. 1994

S Pikuła, and L Epstein, and A Martonosi

Department of Biochemistry and Molecular Biology, State University of New York, Syracuse 13210.

The relationship between the phospholipid composition of sarcoplasmic reticulum and the activity of the Ca2+, Mg2+-stimulated ATPase was analyzed by digestion of membrane phospholipids with phospholipase C and A2 enzymes of diverse specificity and by detergent extraction. Phospholipase C of Clostridium perfringens and Clostridium welchii, that hydrolyze preferentially phosphatidylcholine (PC), inhibited the Ca2+-ATPase activity parallel with the depletion of phosphatidylcholine from the membrane. Phospholipase C of Bacillus cereus hydrolyzed in addition to PC, phosphatidylethanolamine (PE) and phosphatidylserine (PS), causing complete inhibition of Ca2+-stimulated ATPase activity. Digestion of sarcoplasmic reticulum with the phospholipase A2 of snake or bee venom produced similar effects. The phosphatidylinositol (PI)-specific phospholipases of B. cereus and Bacillus thuringiensis caused less than 10% inhibition of the Ca2+-ATPase, accompanied by the hydrolysis of more than 70% of the phosphatidylinositol content of the membrane, without significant change in PC, PE and PS content. The inhibition of ATPase activity by the C type phospholipases was nearly completely reversed by octaethyleneglycol dodecyl ether (C12E8). These experiments suggest that the full phospholipid content of native sarcoplasmic reticulum (congruent to 100 mol phospholipid per mol Ca2+-ATPase), is required for ATPase activity and there is no indication that PE, PS, and PI play a specific role in ATP hydrolysis. Extraction of sarcoplasmic reticulum phospholipids by detergents such as deoxycholate, cholate and C12E8 also caused proportional inhibition of ATPase activity with the decrease in phospholipid content; the parallel extraction of PC, PE and PI left the phospholipid composition largely unchanged during delipidation. These observations do not support the requirement for a 'lipid annulus' of congruent to 30 phospholipid molecules/Ca2+-ATPase as proposed by Hesketh et al. ((1976) Biochemistry 15, 4145-4151) or the specific interaction of phosphatidylethanolamine with the ATPase molecule proposed by Bick et al. ((1991) Arch. Biochem. Biophys. 286, 346-352).

UI	MeSH Term	Description	Entries
D008563	Membrane Lipids	Lipids, predominantly phospholipids, cholesterol and small amounts of glycolipids found in membranes including cellular and intracellular membranes. These lipids may be arranged in bilayers in the membranes with integral proteins between the layers and peripheral proteins attached to the outside. Membrane lipids are required for active transport, several enzymatic activities and membrane formation.	Cell Membrane Lipid,Cell Membrane Lipids,Membrane Lipid,Lipid, Cell Membrane,Lipid, Membrane,Lipids, Cell Membrane,Lipids, Membrane,Membrane Lipid, Cell,Membrane Lipids, Cell
D010716	Phosphatidylinositols	Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to the hexahydroxy alcohol, myo-inositol. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid, myo-inositol, and 2 moles of fatty acids.	Inositide Phospholipid,Inositol Phosphoglyceride,Inositol Phosphoglycerides,Inositol Phospholipid,Phosphoinositide,Phosphoinositides,PtdIns,Inositide Phospholipids,Inositol Phospholipids,Phosphatidyl Inositol,Phosphatidylinositol,Inositol, Phosphatidyl,Phosphoglyceride, Inositol,Phosphoglycerides, Inositol,Phospholipid, Inositide,Phospholipid, Inositol,Phospholipids, Inositide,Phospholipids, Inositol
D010738	Type C Phospholipases	A subclass of phospholipases that hydrolyze the phosphoester bond found in the third position of GLYCEROPHOSPHOLIPIDS. Although the singular term phospholipase C specifically refers to an enzyme that catalyzes the hydrolysis of PHOSPHATIDYLCHOLINE (EC 3.1.4.3), it is commonly used in the literature to refer to broad variety of enzymes that specifically catalyze the hydrolysis of PHOSPHATIDYLINOSITOLS.	Lecithinase C,Phospholipase C,Phospholipases, Type C,Phospholipases C
D010741	Phospholipases A	Phospholipases that hydrolyze one of the acyl groups of phosphoglycerides or glycerophosphatidates.
D010743	Phospholipids	Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.	Phosphatides,Phospholipid
D011817	Rabbits	A burrowing plant-eating mammal with hind limbs that are longer than its fore limbs. It belongs to the family Leporidae of the order Lagomorpha, and in contrast to hares, possesses 22 instead of 24 pairs of chromosomes.	Belgian Hare,New Zealand Rabbit,New Zealand Rabbits,New Zealand White Rabbit,Rabbit,Rabbit, Domestic,Chinchilla Rabbits,NZW Rabbits,New Zealand White Rabbits,Oryctolagus cuniculus,Chinchilla Rabbit,Domestic Rabbit,Domestic Rabbits,Hare, Belgian,NZW Rabbit,Rabbit, Chinchilla,Rabbit, NZW,Rabbit, New Zealand,Rabbits, Chinchilla,Rabbits, Domestic,Rabbits, NZW,Rabbits, New Zealand,Zealand Rabbit, New,Zealand Rabbits, New,cuniculus, Oryctolagus
D003902	Detergents	Purifying or cleansing agents, usually salts of long-chain aliphatic bases or acids, that exert cleansing (oil-dissolving) and antimicrobial effects through a surface action that depends on possessing both hydrophilic and hydrophobic properties.	Cleansing Agents,Detergent Pods,Laundry Detergent Pods,Laundry Pods,Syndet,Synthetic Detergent,Agent, Cleansing,Agents, Cleansing,Cleansing Agent,Detergent,Detergent Pod,Detergent Pod, Laundry,Detergent Pods, Laundry,Detergent, Synthetic,Detergents, Synthetic,Laundry Detergent Pod,Laundry Pod,Pod, Detergent,Pod, Laundry,Pod, Laundry Detergent,Pods, Detergent,Pods, Laundry,Pods, Laundry Detergent,Synthetic Detergents
D000252	Calcium-Transporting ATPases	Cation-transporting proteins that utilize the energy of ATP hydrolysis for the transport of CALCIUM. They differ from CALCIUM CHANNELS which allow calcium to pass through a membrane without the use of energy.	ATPase, Calcium,Adenosinetriphosphatase, Calcium,Ca(2+)-Transporting ATPase,Calcium ATPase,Calcium Adenosinetriphosphatase,Adenosine Triphosphatase, Calcium,Ca2+ ATPase,Calcium-ATPase,ATPase, Ca2+,ATPases, Calcium-Transporting,Calcium Adenosine Triphosphatase,Calcium Transporting ATPases,Triphosphatase, Calcium Adenosine
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
D012519	Sarcoplasmic Reticulum	A network of tubules and sacs in the cytoplasm of SKELETAL MUSCLE FIBERS that assist with muscle contraction and relaxation by releasing and storing calcium ions.	Reticulum, Sarcoplasmic,Reticulums, Sarcoplasmic,Sarcoplasmic Reticulums