Biomaterial Database

Effect of a disulfide-interchange enzyme on the assembly of human secretory immunoglobulin A from immunoglobulin A and free secretory component. 1979

N A Murkofsky, and M E Lamm

A disulfide-interchange enzyme from rat liver microsomes was found to promote binding in vitro of human free secretory component (SC) to dimeric serum-type IgA containing J chain, as assessed by immune precipitation and gel filtration. This effect was greater withe native than with partially reduced SC. Most of the bound SC was covalently linked, as determined by electrophoresis in polyacrylamide gels in detergent. The enzyme did not promote binding of native or partially reduce SC to IgG, IgA monomer, IgA dimer without J chain, or IgM. In the case of IgM, the enzyme did, however, promote covalent bonding of previously non-covalently linked SC. The results overall suggest that a disulfide-interchange enzyme could play a role in vivo in the cell-associated assembly of secretory IgA by promoting the covalent attachment of SC to a dimer of serum-type IgA and that the J chain in the IgA dimer contributes to the enzyme effect.

UI	MeSH Term	Description	Entries
D007070	Immunoglobulin A	Represents 15-20% of the human serum immunoglobulins, mostly as the 4-chain polymer in humans or dimer in other mammals. Secretory IgA (IMMUNOGLOBULIN A, SECRETORY) is the main immunoglobulin in secretions.	IgA,IgA Antibody,IgA1,IgA2,Antibody, IgA
D007128	Immunoglobulin Fragments	Partial immunoglobulin molecules resulting from selective cleavage by proteolytic enzymes or generated through PROTEIN ENGINEERING techniques.	Antibody Fragment,Antibody Fragments,Ig Fragment,Ig Fragments,Immunoglobulin Fragment,Fragment, Antibody,Fragment, Ig,Fragment, Immunoglobulin,Fragments, Antibody,Fragments, Ig,Fragments, Immunoglobulin
D007535	Isomerases	A class of enzymes that catalyze geometric or structural changes within a molecule to form a single product. The reactions do not involve a net change in the concentrations of compounds other than the substrate and the product.(from Dorland, 28th ed) EC 5.	Isomerase
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008862	Microsomes, Liver	Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.	Liver Microsomes,Liver Microsome,Microsome, Liver
D008895	Milk, Human	Milk that is produced by HUMAN MAMMARY GLANDS.	Breast Milk,Human Milk,Milk, Breast
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
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
D003126	Colostrum	The thin, yellow, serous fluid secreted by the mammary glands during pregnancy and immediately postpartum before lactation begins. It consists of immunologically active substances, white blood cells, water, protein, fat, and carbohydrates.	Colostrums
D004220	Disulfides	Chemical groups containing the covalent disulfide bonds -S-S-. The sulfur atoms can be bound to inorganic or organic moieties.	Disulfide