کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2047847 | 1074037 | 2013 | 4 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Spectroscopic characterization of the acid–alkaline transition of a thermophilic cytochrome P450 Spectroscopic characterization of the acid–alkaline transition of a thermophilic cytochrome P450](/preview/png/2047847.png)
The spectroscopic properties of thermophilic cytochrome P450 from the thermoacidophilic crenarchaeon Sulfolobus tokodaii strain 7 (P450st) were investigated in acidic and basic solutions. The resting form of ferric-P450st in weakly-acidic and neutral solutions contained a thiolate/H2O coordinated low-spin heme. Below pH 1.5, P450st underwent cleavage of the Fe–S bond and was converted into apo-P450st. Above pH 8, the acid–alkaline transition due to the deprotonation of the water ligand was observed. The produced thiolate/OH−-coordinated ferric-P450st was stable at room temperature. The pKa value of 8.7 for the transition reflects the protonation properties of the distal side of the heme.
► A thermostable cytochrome P450 exhibits two transitions between pH 1 and 11.
► The heme of P450st dissociates below pH 1.5 by cleavage of the Fe–S bond.
► The deprotonation of the water ligand takes place with the pKa value of 8.7.
Journal: FEBS Letters - Volume 587, Issue 1, 4 January 2013, Pages 94–97