Biomaterial Database

Preparation and properties of acetylcholinesterase from the sea mussel Mytilus edulis. 1978

H Engels, and J Neef, and D von Wachtendonk

The large-scale isolation of an acetylcholinesterase from the haemolymph of the sea mussel mytilus edulis by means of fractional (NH4)2SO4 precipitation, affinity chromatography and isoelectric focusing is described. The yield is about 20% of the initial enzyme activity with a specific activity of 1727 nkat/mg protein. Purification steps are followed by disc electrophoresis, analytical isoelectric focusing and immunoelectrophoresis, showing the enzyme to be homogeneous with an isoelectric point of 4.81 +/- 0.02 and to have an apparent molecular weight of 245,000, which is composed by six equal subunits as judged by C- and N-terminal amino acid analysis. The acetylcholinesterase is a metalloprotein containing three Fe2 ions per subunit (molecular weight 40625); this consists of 351 amino acid and six sugar residues, but contains no sialic acid. As calculated from CD data, the enzyme has about 55% helical structure.

UI	MeSH Term	Description	Entries
D007122	Immunoelectrophoresis	A technique that combines protein electrophoresis and double immunodiffusion. In this procedure proteins are first separated by gel electrophoresis (usually agarose), then made visible by immunodiffusion of specific antibodies. A distinct elliptical precipitin arc results for each protein detectable by the antisera.
D007501	Iron	A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.	Iron-56,Iron 56
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
D002241	Carbohydrates	A class of organic compounds composed of carbon, hydrogen, and oxygen in a ratio of Cn(H2O)n. The largest class of organic compounds, including STARCH; GLYCOGEN; CELLULOSE; POLYSACCHARIDES; and simple MONOSACCHARIDES.	Carbohydrate
D002846	Chromatography, Affinity	A chromatographic technique that utilizes the ability of biological molecules, often ANTIBODIES, to bind to certain ligands specifically and reversibly. It is used in protein biochemistry. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Chromatography, Bioaffinity,Immunochromatography,Affinity Chromatography,Bioaffinity Chromatography
D002942	Circular Dichroism	A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Circular Dichroism, Vibrational,Dichroism, Circular,Vibrational Circular Dichroism
D006458	Hemolymph	The blood/lymphlike nutrient fluid of some invertebrates.	Hemolymphs
D000110	Acetylcholinesterase	An enzyme that catalyzes the hydrolysis of ACETYLCHOLINE to CHOLINE and acetate. In the CNS, this enzyme plays a role in the function of peripheral neuromuscular junctions. EC 3.1.1.7.	Acetylcholine Hydrolase,Acetylthiocholinesterase,Hydrolase, Acetylcholine
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