Abstract
The calcium-binding proteins from avocado fruit mesocarp were investigated and a protein identifiable as a calmodulin was purified to homogeneity by int. al. calcium induced hydrophobic interaction chromatography. The protein has a Mr of 18 900 and exhibits a calcium dependent shift in electrophoretic mobility. Calcium induced changes in UV, fluorescence, and circular dichroism spectra were also observed. A helical content of 17% for the calcium depleted state was calculated which increased to 24% in the presence of saturating concentrations of calcium. The amino acid composition of the protein was closely related to that of the higher plant calmodulins so far analysed. Isoelectric focussing resolved the protein into a doublet with pI values of 3.71 and 3.72. The protein stimulated calmodulin-deficient NAD kinase to the same extent as calmodulin from wheatgerm, but exhibited a very low level of activity as an activator of cyclic monophosphate phosphodiesterase. The similarity and dissimilarity of the avocado protein to other calmodulins are described and discussed.
| Original language | English |
|---|---|
| Pages (from-to) | 705-709 |
| Number of pages | 5 |
| Journal | Phytochemistry |
| Volume | 28 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 1989 |
Keywords
- Lauraceae
- Persea americana
- avocado
- calmodulin.
ASJC Scopus subject areas
- Biochemistry
- Molecular Biology
- Plant Science
- Horticulture