Biomaterial Database

The interaction of tetraiodofluorescein with creatine kinase. 1977

L L Somerville, and F A Quiocho

The dye 2',4',5',7'-tetraiodofluorescein is a potent inhibitor of creatine kinase (ATP:creatine N-phosphotransferase, EC 2.7.3.2) with an apparent competitive inhibition constant with respect to MgATP2- of 2.6 - 10(-5) M. The association of the dye with the enzyme elicited a red shift in the dye's spectrum, indicative of a binding site less polar than water. The dye binds to the enzyme with an equilibrium constant of dissociation of 1.7 - 10(-5) M. MgATP or MgADP competes for the dye-binding site. Creatine binds to creatine kinase-tetraiodofluorescein complex to form a ternary complex and further causes a blue-shift in the spectrum of the bound dye. The binding of the dye to fully active creatine kinase causes conformational change that was monitored by enzyme-bound 2-mercuri-4-nitrophenol, a conformation-dependent "reporter group".

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
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
D003401	Creatine	An amino acid that occurs in vertebrate tissues and in urine. In muscle tissue, creatine generally occurs as phosphocreatine. Creatine is excreted as CREATININE in the urine.
D003402	Creatine Kinase	A transferase that catalyzes formation of PHOSPHOCREATINE from ATP + CREATINE. The reaction stores ATP energy as phosphocreatine. Three cytoplasmic ISOENZYMES have been identified in human tissues: the MM type from SKELETAL MUSCLE, the MB type from myocardial tissue and the BB type from nervous tissue as well as a mitochondrial isoenzyme. Macro-creatine kinase refers to creatine kinase complexed with other serum proteins.	Creatine Phosphokinase,ADP Phosphocreatine Phosphotransferase,ATP Creatine Phosphotransferase,Macro-Creatine Kinase,Creatine Phosphotransferase, ATP,Kinase, Creatine,Macro Creatine Kinase,Phosphocreatine Phosphotransferase, ADP,Phosphokinase, Creatine,Phosphotransferase, ADP Phosphocreatine,Phosphotransferase, ATP Creatine
D005452	Fluoresceins	A family of spiro(isobenzofuran-1(3H),9'-(9H)xanthen)-3-one derivatives. These are used as dyes, as indicators for various metals, and as fluorescent labels in immunoassays.	Tetraiodofluorescein
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining
D013053	Spectrophotometry	The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.