Biomaterial Database

Effect of modification on physico-chemical and biological properties of haptoglobin. Acetylation, iodination and nitration. 1975

W Dobryszycka, and I Bec-Katnik

Human haptoglobin (Hp) type 2-1 was modified with N-acetylimidazole, iodine or tetranitromethane (TNM), and the ability of the obtained derivatives to form with haemoglobin (Hb) complexes with peroxidase activity, was estimated. At low reagent to protein molar ratios, 11 tyrosine residues were nitrated, 12 acetylated and 13 iodinated. The biological activity of NO2-Hp and I-Hp amounted to 40% of the activity of native Hp whereas the activity of Ac-Hp only to 16%. The derivatives modified at high ratios of N-acetylimidazole or iodine lost the ability to bind with Hb. Deacylation. of tyrosines and partial liberation of acetylated xi-amino groups resulted in partial recovery of the activity. As demonstrated by polyacrylamide-gel electrophoresis, the modification of Hp with high excess of TNM or iodine induced polymer formation

UI	MeSH Term	Description	Entries
D007093	Imidazoles	Compounds containing 1,3-diazole, a five membered aromatic ring containing two nitrogen atoms separated by one of the carbons. Chemically reduced ones include IMIDAZOLINES and IMIDAZOLIDINES. Distinguish from 1,2-diazole (PYRAZOLES).
D007455	Iodine	A nonmetallic element of the halogen group that is represented by the atomic symbol I, atomic number 53, and atomic weight of 126.90. It is a nutritionally essential element, especially important in thyroid hormone synthesis. In solution, it has anti-infective properties and is used topically.	Iodine-127,Iodine 127
D010544	Peroxidases		Ovoperoxidase
D011108	Polymers	Compounds formed by the joining of smaller, usually repeating, units linked by covalent bonds. These compounds often form large macromolecules (e.g., BIOPOLYMERS; PLASTICS).	Polymer
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
D002621	Chemistry	A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.
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
D006242	Haptoglobins	Plasma glycoproteins that form a stable complex with hemoglobin to aid the recycling of heme iron. They are encoded in man by a gene on the short arm of chromosome 16.	Haptoglobin
D006454	Hemoglobins	The oxygen-carrying proteins of ERYTHROCYTES. They are found in all vertebrates and some invertebrates. The number of globin subunits in the hemoglobin quaternary structure differs between species. Structures range from monomeric to a variety of multimeric arrangements.	Eryhem,Ferrous Hemoglobin,Hemoglobin,Hemoglobin, Ferrous
D000107	Acetylation	Formation of an acetyl derivative. (Stedman, 25th ed)	Acetylations