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Chemical modification of glycerinated stalks shows tyrosine residues essential for spasmoneme contraction of Vorticella sp.
- Source :
-
Zoological science [Zoolog Sci] 2004 May; Vol. 21 (5), pp. 527-32. - Publication Year :
- 2004
-
Abstract
- Chemical modification of glycerinated stalks of Vorticella with TNM is used to investigate the role of tyrosine residues in the Ca(2+)-induced contraction of the spasmoneme. Tetranitromethane (TNM) is often employed as a specific reagent for the nitration of tyrosine residues in a protein at neutral and slightly alkaline pHs although TNM can also oxidize cysteine residues in the acidic and neutral pH range. Prior incubation with Ca(2+) of stalks to be treated with TNM can protect the spasmoneme from irreversible denaturation. On the other hand, TNM treatment in the absence of free Ca(2+) causes an irreversible denaturation of the spasmoneme. It was revealed by us that an isolated Ca(2+)-binding protein called spasmin could not bind with Ca(2+) after TNM treatment, even if the treatment was performed in the presence of Ca(2+). In an additional experiment, we confirmed that the chemical modification of cysteine residues in the spasmoneme with N-7-dimethyl-amino-4methyl- coumarinyl- maleimide (DACM) has no effect on the contractibility. These results suggest that tyrosine residues in spasmin are essential for spasmoneme contraction and are protected from TNM in the presence of Ca(2+) when spasmin binds with its receptor protein in the spasmoneme.
- Subjects :
- Animal Structures metabolism
Animals
Calcium metabolism
China
Dose-Response Relationship, Drug
Electrophoresis, Polyacrylamide Gel
Hydrogen-Ion Concentration
Maleimides metabolism
Maleimides pharmacology
Protein Binding drug effects
Protein Denaturation drug effects
Tetranitromethane metabolism
Tyrosine metabolism
Animal Structures drug effects
Contractile Proteins metabolism
Oligohymenophorea metabolism
Protozoan Proteins metabolism
Tetranitromethane pharmacology
Subjects
Details
- Language :
- English
- ISSN :
- 0289-0003
- Volume :
- 21
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- Zoological science
- Publication Type :
- Academic Journal
- Accession number :
- 15170056
- Full Text :
- https://doi.org/10.2108/zsj.21.527