ISSN:
1574-6968
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
The poly(ADP-ribose) polymerase-like thermozyme purified from Sulfolobus solfataricus was characterised with respect to some physico-chemical properties. The archaeal protein exhibited a scarce electrophoretic mobility at both pH 2.9 and pH 7.5. Determination of the isoelectric point (pI=7.0–7.2) allowed us to understand the reason for the limited migration at pH 7.5, while amino acid composition analysis showed a moderate content of basic residues, which reduced mobility at pH 2.9. With respect to the charge, the archaeal enzyme behaved differently from the eukaryotic thermolabile poly(ADP-ribose) polymerase, described as a basic protein (pI=9.5). Well known inhibitors of the mesophilic polymerase like Zn2+, nicotinamide and 3-aminobenzamide exerted a smaller effect on the enzyme from S. solfataricus, reducing the activity by at most 50%. Mg2+ was a positive effector, although in a dose-dependent manner. It influenced the fluorescence spectrum of the archaeal protein, whereas NaCl had no effect.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1574-6968.2000.tb09351.x
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