Biomaterial Database

Conformational changes and loss of opsonic function in frozen or heat-treated plasma fibronectin. 1984

B J Boughton, and A Simpson, and C Wharton

Using human peripheral blood monocytes to assay opsonic protein activity, we have examined the efficiency of various procedures for isolating fibronectin from plasma for experimental or therapeutic use. In addition, we have assessed the protein's opsonic activity after cold storage, and after heat treatment to inactivate hepatitis virus. The purification procedures recovered only 30% of available plasma fibronectin whilst cold storage and heat treatment of the purified protein removed all of its remaining opsonic activity. This was associated with no alteration in overall molecular weight or in subunit size but was accompanied by changes in ultraviolet spectrum, suggesting a conformational change in the protein structure. Initial experiments to protect the purified protein against these changes were unsuccessful and unless further attempts are more encouraging, fresh-frozen plasma may be the only current economic source of opsonically active fibronectin. Since this would waste other valuable proteins required for other purposes, the widespread use of plasma fibronectin outside of clinical trials may be unjustified at this present time.

UI	MeSH Term	Description	Entries
D009895	Opsonin Proteins	Proteins that bind to particles and cells to increase susceptibility to PHAGOCYTOSIS, especially ANTIBODIES bound to EPITOPES that attach to FC RECEPTORS. COMPLEMENT C3B may also participate.	Opsonin,Opsonin Protein,Opsonins,Protein, Opsonin
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
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
D004591	Electrophoresis, Polyacrylamide Gel	Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.	Polyacrylamide Gel Electrophoresis,SDS-PAGE,Sodium Dodecyl Sulfate-PAGE,Gel Electrophoresis, Polyacrylamide,SDS PAGE,Sodium Dodecyl Sulfate PAGE,Sodium Dodecyl Sulfate-PAGEs
D005353	Fibronectins	Glycoproteins found on the surfaces of cells, particularly in fibrillar structures. The proteins are lost or reduced when these cells undergo viral or chemical transformation. They are highly susceptible to proteolysis and are substrates for activated blood coagulation factor VIII. The forms present in plasma are called cold-insoluble globulins.	Cold-Insoluble Globulins,LETS Proteins,Fibronectin,Opsonic Glycoprotein,Opsonic alpha(2)SB Glycoprotein,alpha 2-Surface Binding Glycoprotein,Cold Insoluble Globulins,Globulins, Cold-Insoluble,Glycoprotein, Opsonic,Proteins, LETS,alpha 2 Surface Binding Glycoprotein
D005615	Freezing	Liquids transforming into solids by the removal of heat.	Melting
D006358	Hot Temperature	Presence of warmth or heat or a temperature notably higher than an accustomed norm.	Heat,Hot Temperatures,Temperature, Hot,Temperatures, Hot
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D013056	Spectrophotometry, Ultraviolet	Determination of the spectra of ultraviolet absorption by specific molecules in gases or liquids, for example Cl2, SO2, NO2, CS2, ozone, mercury vapor, and various unsaturated compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Ultraviolet Spectrophotometry