Effect of pH and Ionic Strength on the Heat Stability of Rapeseed 12S Globulin (Cruciferin) by the ANS Fluorescence Method
✍ Scribed by Folawiyo, Yetunde L; Apenten, Richard K Owusu
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 587 KB
- Volume
- 70
- Category
- Article
- ISSN
- 0022-5142
No coin nor oath required. For personal study only.
✦ Synopsis
The heat stability of rapeseed 12s globulin (cruciferin) was examined using 8-anilinonaphthalene-l-sulphonic acid (ANS) as a fluorescence probe. Heating cruciferin (0.06-0.3 mg ml-in 10 mM glycyl-glycyl piperizine buffer, pH 7.0, with 0.1-1.0 M NaCl) for 20 min increased its hydrophobicity as monitored by ANS fluorescence measurements. The mid-point temperature for the heat effect (T',) increased linearly with increasing solvent pH (T, ("C) = 4.16 pH + 41 ( p = 0.1)) or sodium chloride concentration (T, ("C) = 14.7 [NaCl] + 71 (pH = 7.0)). The range of T, values for cruciferin was 45-96°C. At 20°C cruciferin was unstable at pH c 3.0 but relatively stable under alkaline conditions (pH 8-10). Though possessing an oligomeric structure, cruciferin appears to heat denature in accordance with the two-stage deactivation model for simple globular proteins.