Biomaterial Database

The use of monoclonal antibodies to probe human apolipoprotein B structure and function. 1985

R W Milne, and Y L Marcel

Apolipoprotein (apo) B plays an important role in plasma lipid transport and in the maintenance of cholesterol homeostasis. Attempts to determine the structure of apo B have been hampered by technical obstacles resulting from its chemical and physical properties. Recently monoclonal antibodies (Mabs) against human apo B have been used as probes to study apo B structure and heterogeneity. Certain Mabs are capable of blocking binding of low density lipoprotein (LDL) apo B to the cell surface LDL receptor, which presumably reflects the proximity of their antigenic determinants to the receptor recognition domain. The distribution of antigenic determinants recognized by Mabs has been studied on the hepatic (apo B-100) and intestinal (apo B-48) forms of apo B and on fragments generated by limited proteolysis of apo B. Some Mabs are specific for apo B-100, whereas others cross-react with apo B-48. Apo B-100 specific Mabs coupled to Sepharose have been used to isolate separately apo-B-containing lipoproteins of intestinal and hepatic origin and their respective lipid and apolipoprotein compositions have been determined. Using the separated fractions it has been shown that apo B-100, but not apo B-48, can react with the LDL receptor. Most Mabs failed to react with apo B which had been delipidated and resolubilized, but in some cases immunoreactivity could be recovered if the solubilized apo B were reincorporated into lipid vesicles. These experiments showed that different determinants had different lipid requirements for their expression.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D008081	Liposomes	Artificial, single or multilaminar vesicles (made from lecithins or other lipids) that are used for the delivery of a variety of biological molecules or molecular complexes to cells, for example, drug delivery and gene transfer. They are also used to study membranes and membrane proteins.	Niosomes,Transferosomes,Ultradeformable Liposomes,Liposomes, Ultra-deformable,Liposome,Liposome, Ultra-deformable,Liposome, Ultradeformable,Liposomes, Ultra deformable,Liposomes, Ultradeformable,Niosome,Transferosome,Ultra-deformable Liposome,Ultra-deformable Liposomes,Ultradeformable Liposome
D010446	Peptide Fragments	Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.	Peptide Fragment,Fragment, Peptide,Fragments, Peptide
D011110	Polymorphism, Genetic	The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.	Gene Polymorphism,Genetic Polymorphism,Polymorphism (Genetics),Genetic Polymorphisms,Gene Polymorphisms,Polymorphism, Gene,Polymorphisms (Genetics),Polymorphisms, Gene,Polymorphisms, Genetic
D004655	Emulsions	Colloids formed by the combination of two immiscible liquids such as oil and water. Lipid-in-water emulsions are usually liquid, like milk or lotion. Water-in-lipid emulsions tend to be creams. The formation of emulsions may be aided by amphiphatic molecules that surround one component of the system to form MICELLES.	Emulsion
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000911	Antibodies, Monoclonal	Antibodies produced by a single clone of cells.	Monoclonal Antibodies,Monoclonal Antibody,Antibody, Monoclonal
D000939	Epitopes	Sites on an antigen that interact with specific antibodies.	Antigenic Determinant,Antigenic Determinants,Antigenic Specificity,Epitope,Determinant, Antigenic,Determinants, Antigenic,Specificity, Antigenic
D001055	Apolipoproteins B	Major structural proteins of triacylglycerol-rich LIPOPROTEINS. There are two forms, apolipoprotein B-100 and apolipoprotein B-48, both derived from a single gene. ApoB-100 expressed in the liver is found in low-density lipoproteins (LIPOPROTEINS, LDL; LIPOPROTEINS, VLDL). ApoB-48 expressed in the intestine is found in CHYLOMICRONS. They are important in the biosynthesis, transport, and metabolism of triacylglycerol-rich lipoproteins. Plasma Apo-B levels are high in atherosclerotic patients but non-detectable in ABETALIPOPROTEINEMIA.	Apo-B,Apo B,ApoB,Apoprotein (B),Apoproteins B
D014357	Trypsin	A serine endopeptidase that is formed from TRYPSINOGEN in the pancreas. It is converted into its active form by ENTEROPEPTIDASE in the small intestine. It catalyzes hydrolysis of the carboxyl group of either arginine or lysine. EC 3.4.21.4.	Tripcellim,Trypure,beta-Trypsin,beta Trypsin