Kinetic study of the activation process of frog epidermis pro-tyrosinase by trypsin. 1983

J D Galindo, and R Peñafiel, and R Varon, and E Pedreño, and F Garcia-Carmona, and F García-Cánovas

1. The rate of tyrosinase formation has been calculated by coupling the activatory process of frog epidermis pro-tyrosinase by trypsin to the oxidation of L-DOPA to dopachrome. Under certain conditions ([trypsin]/[pro-tyrosinase] greater than or equal to 300), the lag period of the coupled reactions, tau, is independent of trypsin concentration. 2. The specific rate constant of tyrosinase formation at different temperatures has been calculated, ranging from 0.025 sec-1, at 5 degrees C to 0.248 sec-1, at 30 degrees C. 3. Thermodynamic parameters of the activatory process (delta G not equal to = + 18.5 kcal/mol; delta H not equal to = + 14.8 kcal/mol; delta S not equal to = -12.4 e.u.; Ea = + 15.3 kcal/mol), have been determined by the study of the system at different temperatures. These values are characteristic for a normal chemical reaction. 4. From these kinetic data, the order of products formation in the proteolytic step, can be determined, active tyrosinase being the last product released.

UI MeSH Term Description Entries
D007700 Kinetics The rate dynamics in chemical or physical systems.
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
D011893 Rana esculenta An edible species of the family Ranidae, occurring in Europe and used extensively in biomedical research. Commonly referred to as "edible frog". Pelophylax esculentus
D004156 Catechol Oxidase An enzyme of the oxidoreductase class that catalyzes the reaction between catechol and oxygen to yield benzoquinone and water. It is a complex of copper-containing proteins that acts also on a variety of substituted catechols. EC 1.10.3.1. Diphenol Oxidases,Diphenol Oxidase,Polyphenol Oxidase,Polyphenoloxidase,Oxidase, Catechol,Oxidase, Diphenol,Oxidase, Polyphenol,Oxidases, Diphenol
D004789 Enzyme Activation Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme. Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D004792 Enzyme Precursors Physiologically inactive substances that can be converted to active enzymes. Enzyme Precursor,Proenzyme,Proenzymes,Zymogen,Zymogens,Precursor, Enzyme,Precursors, Enzyme
D004817 Epidermis The external, nonvascular layer of the skin. It is made up, from within outward, of five layers of EPITHELIUM: (1) basal layer (stratum basale epidermidis); (2) spinous layer (stratum spinosum epidermidis); (3) granular layer (stratum granulosum epidermidis); (4) clear layer (stratum lucidum epidermidis); and (5) horny layer (stratum corneum epidermidis).
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
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
D014442 Monophenol Monooxygenase An enzyme of the oxidoreductase class that catalyzes the reaction between L-tyrosine, L-dopa, and oxygen to yield L-dopa, dopaquinone, and water. It is a copper protein that acts also on catechols, catalyzing some of the same reactions as CATECHOL OXIDASE. EC 1.14.18.1. Dopa Oxidase,Phenoloxidase,Tyrosinase,Cresolase,Phenol Oxidase,Phenoloxidase A,Phenoloxidase B,Monooxygenase, Monophenol,Oxidase, Dopa,Oxidase, Phenol

Related Publications

J D Galindo, and R Peñafiel, and R Varon, and E Pedreño, and F Garcia-Carmona, and F García-Cánovas
July 1988, Biophysical chemistry,
J D Galindo, and R Peñafiel, and R Varon, and E Pedreño, and F Garcia-Carmona, and F García-Cánovas
January 1979, General pharmacology,
J D Galindo, and R Peñafiel, and R Varon, and E Pedreño, and F Garcia-Carmona, and F García-Cánovas
March 1978, Revista espanola de fisiologia,
J D Galindo, and R Peñafiel, and R Varon, and E Pedreño, and F Garcia-Carmona, and F García-Cánovas
June 1979, Revista espanola de fisiologia,
J D Galindo, and R Peñafiel, and R Varon, and E Pedreño, and F Garcia-Carmona, and F García-Cánovas
December 1973, The Yale journal of biology and medicine,
J D Galindo, and R Peñafiel, and R Varon, and E Pedreño, and F Garcia-Carmona, and F García-Cánovas
October 1984, Biochimica et biophysica acta,
J D Galindo, and R Peñafiel, and R Varon, and E Pedreño, and F Garcia-Carmona, and F García-Cánovas
August 1996, The international journal of biochemistry & cell biology,
J D Galindo, and R Peñafiel, and R Varon, and E Pedreño, and F Garcia-Carmona, and F García-Cánovas
May 1974, The Journal of biological chemistry,
J D Galindo, and R Peñafiel, and R Varon, and E Pedreño, and F Garcia-Carmona, and F García-Cánovas
September 1999, Journal of agricultural and food chemistry,
J D Galindo, and R Peñafiel, and R Varon, and E Pedreño, and F Garcia-Carmona, and F García-Cánovas
April 1984, Applied biochemistry and biotechnology,
Copied contents to your clipboard!