| Monooxygenase activity of Octopus vulgaris hemocyanin. | |
| | |
MedLine Citation:
|
PMID: 18553939 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Octopus vulgaris hemocyanin ( Ov-Hc) and one of its minimal functional units ( Ov-g) have been purified, and their spectroscopic features and monooxygenase (phenolase) activity have been examined in detail. The oxy forms of both Ov-Hc and Ov-g are stable in 0.5 M borate buffer (pH 9.0) even in the presence of a high concentration of urea at 25 degrees C; approximately 90 and approximately 75% of the (mu-eta (2):eta (2)-peroxo)dicopper(II) species of Ov-Hc and Ov-g, respectively, remained unchanged after argon (Ar) gas flushing of the sample solutions for 1 h. The catalytic activity of Ov-g in the oxygenation reaction (multiturnover reaction) of 4-methylphenol ( p-cresol) to 4-methyl-1,2-dihydroxybenzene (4-methylcatechol) was higher than that of Ov-Hc, and its catalytic activity was further accelerated by the addition of urea. Kinetic deuterium isotope effect analysis and Hammett analysis using a series of phenol derivatives under anaerobic conditions (single-turnover reaction) have indicated that the monooxygenation reaction of phenols to catechols by the peroxo species of oxyhemocyanin proceeds via electrophilic aromatic substitution mechanism as in the case of tyrosinase. The effect of urea on the redox functions of oxyhemocyanin is discussed on the basis of the spectroscopic analysis and reactivity studies. |
| | |
Authors:
|
Kenji Suzuki; Chizu Shimokawa; Chiyuki Morioka; Shinobu Itoh |
Related Documents
:
|
7535099 - Purine functional groups in essential residues of the hairpin ribozyme required for cat... 11258909 - Characterization of the transition-state structure of the reaction of kanamycin nucleot... 22443769 - A detailed test study of barrier heights for the ho(2) + h(2)o + o(3) reaction with var... 22491399 - Mechanistic aspects of photo-induced formation of peroxide ions on the surface of cubic... 9718309 - Coupling of cobalt-carbon bond homolysis and hydrogen atom abstraction in adenosylcobal... 19039 - Phosphoglycerate mutase from wheat germ: studies with isotopically labeled 3-phospho-d-... 14989669 - Experimental and computational studies of the metal-metal stretching vibration in x(3)m... 18243779 - Host-guest interaction of l-tyrosine with beta-cyclodextrin. 11442039 - Sensitive determination of metal ions by liquid chromatography with tris(2,2'-bipyridin... |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2008-06-14 |
Journal Detail:
|
Title: Biochemistry Volume: 47 ISSN: 1520-4995 ISO Abbreviation: Biochemistry Publication Date: 2008 Jul |
Date Detail:
|
Created Date: 2008-07-01 Completed Date: 2008-07-16 Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 0370623 Medline TA: Biochemistry Country: United States |
Other Details:
|
Languages: eng Pagination: 7108-15 Citation Subset: IM |
Affiliation:
|
Department of Chemistry, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Aerobiosis Anaerobiosis Animals Binding Sites Catalysis Catechols / chemistry, metabolism Circular Dichroism Hemocyanin / chemistry, metabolism* Mixed Function Oxygenases / chemistry, metabolism* Octopodiformes / enzymology* Phenols / chemistry, metabolism Protein Structure, Quaternary Substrate Specificity Time Factors |
| Chemical | |
Reg. No./Substance:
|
0/Catechols; 0/Phenols; 0/oxy-beta-hemocyanin; 9013-72-3/Hemocyanin; EC 1.-/Mixed Function Oxygenases |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Diverse regulation of SNF2h chromatin remodeling by noncatalytic subunits.
Next Document: Effects of flow rate on sensitivity and affinity in flow injection biosensor systems studied by 55-M...