Biomaterial Database

Human serum albumin bearing covalently attached iron(II) porphyrins as O2-coordination sites. 2005

Rong-Min Wang, and Teruyuki Komatsu, and Akito Nakagawa, and Eishun Tsuchida

Advanced Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.

Tetrakis{(alpha,alpha,alpha,alpha-o-pivalamido)phenyl}porphinatoiron(II) with a bifunctional tail possessing an axially coordinated imidazolyl group and a protein attachable succinimidyl(glutamyl) group (FeP-GluSu) has been synthesized. It can efficiently react with the lysine residues of recombinant human serum albumin (rHSA), giving a new albumin-heme conjugate [rHSA(FeP-Glu)]. MALDI-TOFMS showed a distinct molecular ion peak at m/z 70 643, which indicates that three FeP-Glu molecules were covalently linked to the rHSA scaffold. The binding number of FeP-Glu is approximately three (mol/mol) and independent of the mixing ratio. The CD spectrum and Native PAGE revealed that the albumin structure remained unaltered after the covalent bonding of the hemes. This rHSA(FeP-Glu) conjugate can bind and release O2 reversibly under physiological conditions (pH 7.3, 37 degrees C) in the same manner as hemoglobin and myoglobin. The O2-adduct complex had a remarkably long lifetime (tau(1/2): 5 h). The O2-binding affinity [P(1/2)O2: 27 Torr] was identical to that of human red cells. Laser flash photolysis experiments gave the O2- and CO-association rate constants and suggested that there are two different geometries of the imidazole binding to the central ion.

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).
D008239	Lysine	An essential amino acid. It is often added to animal feed.	Enisyl,L-Lysine,Lysine Acetate,Lysine Hydrochloride,Acetate, Lysine,L Lysine
D008652	Mesoporphyrins	Porphyrins with four methyl, two ethyl, and two propionic acid side chains attached to the pyrrole rings.
D008956	Models, Chemical	Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.	Chemical Models,Chemical Model,Model, Chemical
D010100	Oxygen	An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.	Dioxygen,Oxygen-16,Oxygen 16
D010782	Photolysis	Chemical bond cleavage reactions resulting from absorption of radiant energy.	Photodegradation
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
D006420	Hemeproteins	Proteins that contain an iron-porphyrin, or heme, prosthetic group resembling that of hemoglobin. (From Lehninger, Principles of Biochemistry, 1982, p480)	Hemeprotein,Heme Protein,Heme Proteins,Protein, Heme,Proteins, Heme
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
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