Biomaterial Database

Aggregation of band 3 in hereditary ovalocytic red blood cell membranes. Electron microscopy and protein rotational diffusion studies. 1993

A Che, and R J Cherry, and L H Bannister, and A R Dluzewski

Department of Chemistry and Biological Chemistry, University of Essex, Wivenhoe Park, Colchester, UK.

Microaggregation of band 3 proteins in hereditary ovalocytic membranes was investigated by rotational diffusion measurements and by electron microscopy. It was previously shown that band 3 in ovalocytic membranes has decreased rotational mobility compared with band 3 in normal cells (Tilley, L., Nash, G.B., Jones, G.L. and Sawyer, W.L. (1991) J. Membr. Biol. 121, 59-66). This result could arise from either altered interactions with cytoskeletal proteins or from band 3 microaggregation. In the present study it was found that removal of spectrin and actin from the membrane had no effect on the rotational mobility of ovalocytic band 3. Additional removal of ankyrin and band 4.1, as well as cleavage of the cytoplasmic domain of band 3 with trypsin, did enhance band 3 mobility, as is the case in the membranes from normal cells. However, the rotational mobility of ovalocytic band 3 was always considerably less than that of normal band 3 under the same conditions. Scanning electron microscopy and low power electron micrographs of freeze-fracture replicas revealed that the surfaces of ovalocytes were more irregular than those of normal erythrocytes. At higher magnification, numerous linearly arranged intramembranous particles were observed on the P-faces of freeze-fractured ovalocytes but not on normal cells. These clusters consist of straight or slightly curved lines of 10-15 particles in single rows. From these results it is deduced that the reduced rotational mobility of band 3 in ovalocytes is a consequence of the formation of microaggregates, which are very probably induced by the mutation in the membrane-bound domain of ovalocytic band 3.

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
D008855	Microscopy, Electron, Scanning	Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.	Scanning Electron Microscopy,Electron Scanning Microscopy,Electron Microscopies, Scanning,Electron Microscopy, Scanning,Electron Scanning Microscopies,Microscopies, Electron Scanning,Microscopies, Scanning Electron,Microscopy, Electron Scanning,Microscopy, Scanning Electron,Scanning Electron Microscopies,Scanning Microscopies, Electron,Scanning Microscopy, Electron
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D009904	Optical Rotation	The rotation of linearly polarized light as it passes through various media.	Optical Activity,Activity, Optical,Rotation, Optical
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D004612	Elliptocytosis, Hereditary	An intrinsic defect of erythrocytes inherited as an autosomal dominant trait. The erythrocytes assume an oval or elliptical shape.	Ovalocytosis, Hereditary,Elliptocytoses, Hereditary,Hereditary Elliptocytoses,Hereditary Elliptocytosis,Hereditary Ovalocytoses,Hereditary Ovalocytosis,Ovalocytoses, Hereditary
D004910	Erythrocyte Membrane	The semi-permeable outer structure of a red blood cell. It is known as a red cell 'ghost' after HEMOLYSIS.	Erythrocyte Ghost,Red Cell Cytoskeleton,Red Cell Ghost,Erythrocyte Cytoskeleton,Cytoskeleton, Erythrocyte,Cytoskeleton, Red Cell,Erythrocyte Cytoskeletons,Erythrocyte Ghosts,Erythrocyte Membranes,Ghost, Erythrocyte,Ghost, Red Cell,Membrane, Erythrocyte,Red Cell Cytoskeletons,Red Cell Ghosts
D005614	Freeze Fracturing	Preparation for electron microscopy of minute replicas of exposed surfaces of the cell which have been ruptured in the frozen state. The specimen is frozen, then cleaved under high vacuum at the same temperature. The exposed surface is shadowed with carbon and platinum and coated with carbon to obtain a carbon replica.	Fracturing, Freeze,Fracturings, Freeze,Freeze Fracturings
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults