Biomaterial Database

Separation of equine IgG subclasses (IgGa, IgGb and IgG(T)) using their differential binding characteristics for staphylococcal protein A and streptococcal protein G. 1996

A S Sheoran, and M A Holmes

Department of Clinical Veterinary Medicine, University of Cambridge, UK.

Equine IgG possesses four well-defined subisotypes, designated IgGa, IgGb, IgGc and IgG(T) on the basis of their increasing anodal mobility in electrophoresis. However, the preparation of IgGa and IgGb reference proteins has not previously been reported. Certain bacterial cell wall proteins, termed protein A and protein G, have been used for purification of IgG subisotypes from the serum of domestic animals which, combined with other techniques utilising differences in the physico-chemical properties of the proteins, has allowed the purification of Ig isotypes. This paper describes purification of the subisotypes of equine IgG. Purification of IgGa and IgGb was achieved by the separation of a 'fall-through' peak from ion-exchange chromatography consisting of IgGa and IgGb into two fractions (peaks C and D) by FPLC protein A and protein G affinity chromatography. Peak C consisted of IgGb and peak D consisted of IgGa exhibiting slightly faster cathodal migration than peak C in IEP analysis. Affinity chromatography using protein A and G columns also indicated that there may be two different components of IgG(T); one with a low affinity for protein G and the other having a greater affinity for protein G.

UI	MeSH Term	Description	Entries
D007074	Immunoglobulin G	The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.	Gamma Globulin, 7S,IgG,IgG Antibody,Allerglobuline,IgG(T),IgG1,IgG2,IgG2A,IgG2B,IgG3,IgG4,Immunoglobulin GT,Polyglobin,7S Gamma Globulin,Antibody, IgG,GT, Immunoglobulin
D007132	Immunoglobulin Isotypes	The classes of immunoglobulins found in any species of animal. In man there are nine classes that migrate in five different groups in electrophoresis; they each consist of two light and two heavy protein chains, and each group has distinguishing structural and functional properties.	Antibody Class,Ig Isotype,Ig Isotypes,Immunoglobulin Class,Immunoglobulin Isotype,Antibody Classes,Immunoglobulin Classes,Class, Antibody,Class, Immunoglobulin,Classes, Antibody,Classes, Immunoglobulin,Isotype, Ig,Isotype, Immunoglobulin,Isotypes, Ig,Isotypes, Immunoglobulin
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D006736	Horses	Large, hoofed mammals of the family EQUIDAE. Horses are active day and night with most of the day spent seeking and consuming food. Feeding peaks occur in the early morning and late afternoon, and there are several daily periods of rest.	Equus caballus,Equus przewalskii,Horse, Domestic,Domestic Horse,Domestic Horses,Horse,Horses, Domestic
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
D000942	Antigens, Bacterial	Substances elaborated by bacteria that have antigenic activity.	Bacterial Antigen,Bacterial Antigens,Antigen, Bacterial
D001426	Bacterial Proteins	Proteins found in any species of bacterium.	Bacterial Gene Products,Bacterial Gene Proteins,Gene Products, Bacterial,Bacterial Gene Product,Bacterial Gene Protein,Bacterial Protein,Gene Product, Bacterial,Gene Protein, Bacterial,Gene Proteins, Bacterial,Protein, Bacterial,Proteins, Bacterial
D001666	Binding Sites, Antibody	Local surface sites on antibodies which react with antigen determinant sites on antigens (EPITOPES.) They are formed from parts of the variable regions of FAB FRAGMENTS.	Antibody Binding Sites,Paratopes,Antibody Binding Site,Binding Site, Antibody,Paratope
D013205	Staphylococcal Protein A	A protein present in the cell wall of most Staphylococcus aureus strains. The protein selectively binds to the Fc region of human normal and myeloma-derived IMMUNOGLOBULIN G. It elicits antibody activity and may cause hypersensitivity reactions due to histamine release; has also been used as cell surface antigen marker and in the clinical assessment of B lymphocyte function.	Protein A,Protein A, Staphylococcal
D013291	Streptococcus	A genus of gram-positive, coccoid bacteria whose organisms occur in pairs or chains. No endospores are produced. Many species exist as commensals or parasites on man or animals with some being highly pathogenic. A few species are saprophytes and occur in the natural environment.