Abstract
Phoborhodopsin (pR; also called sensory rhodopsin II, sRII) is a receptor of negative phototaxis of Halobacterium salinarum, and pharaonis phoborhodopsin (ppR; also pharaonis sensory rhodopsin II, psRII) is a corresponding protein of Natronobacterium pharaonis. These receptors contain retinal as a chromophore which binds to a lysine residue via Schiff base. This Schiff base can be cleaved with hydroxylamine to loose their color (bleaching). In dark, the bleaching rate of ppR was very slow whereas illumination accelerated considerably the bleaching rate. Addition of azide accelerated the decay of the M-intermediate while its formation (decay of the L-intermediate) is not affected. The bleaching rate of ppR under illumination was decreased by addition of azide. Essentially no reactivity with hydroxylamine under illumination was observed in the case of D75N mutant which lacks the M-intermediate in its photocycle. Moreover, we provided illumination by flashes to ppR in the presence of varying concentrations of azide to measure the bleaching rate per one flash. A good correlation was obtained between the rate and the mean residence time, MRT, which was calculated from flash photolysis data of the M-decay. These findings reveal that water-soluble hydroxylamine reacts selectively with the M-intermediate and its implication was discussed.
| Original language | English |
|---|---|
| Pages (from-to) | 152-158 |
| Number of pages | 7 |
| Journal | BBA - Biomembranes |
| Volume | 1514 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Sep 3 2001 |
| Externally published | Yes |
Fingerprint
Keywords
- Bacteriorhodopsin
- Bleach of chromophore
- M-Intermediate
- Natronobacterium pharaonis
- Pharaonis sensory rhodopsin II
ASJC Scopus subject areas
- Biochemistry
- Biophysics
- Cell Biology
Cite this
Selective reaction of hydroxylamine with chromophore during the photocycle of pharaonis phoborhodopsin. / Iwamoto, Masayuki; Sudo, Yuki; Shimono, Kazumi; Kamo, Naoki.
In: BBA - Biomembranes, Vol. 1514, No. 1, 03.09.2001, p. 152-158.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Selective reaction of hydroxylamine with chromophore during the photocycle of pharaonis phoborhodopsin
AU - Iwamoto, Masayuki
AU - Sudo, Yuki
AU - Shimono, Kazumi
AU - Kamo, Naoki
PY - 2001/9/3
Y1 - 2001/9/3
N2 - Phoborhodopsin (pR; also called sensory rhodopsin II, sRII) is a receptor of negative phototaxis of Halobacterium salinarum, and pharaonis phoborhodopsin (ppR; also pharaonis sensory rhodopsin II, psRII) is a corresponding protein of Natronobacterium pharaonis. These receptors contain retinal as a chromophore which binds to a lysine residue via Schiff base. This Schiff base can be cleaved with hydroxylamine to loose their color (bleaching). In dark, the bleaching rate of ppR was very slow whereas illumination accelerated considerably the bleaching rate. Addition of azide accelerated the decay of the M-intermediate while its formation (decay of the L-intermediate) is not affected. The bleaching rate of ppR under illumination was decreased by addition of azide. Essentially no reactivity with hydroxylamine under illumination was observed in the case of D75N mutant which lacks the M-intermediate in its photocycle. Moreover, we provided illumination by flashes to ppR in the presence of varying concentrations of azide to measure the bleaching rate per one flash. A good correlation was obtained between the rate and the mean residence time, MRT, which was calculated from flash photolysis data of the M-decay. These findings reveal that water-soluble hydroxylamine reacts selectively with the M-intermediate and its implication was discussed.
AB - Phoborhodopsin (pR; also called sensory rhodopsin II, sRII) is a receptor of negative phototaxis of Halobacterium salinarum, and pharaonis phoborhodopsin (ppR; also pharaonis sensory rhodopsin II, psRII) is a corresponding protein of Natronobacterium pharaonis. These receptors contain retinal as a chromophore which binds to a lysine residue via Schiff base. This Schiff base can be cleaved with hydroxylamine to loose their color (bleaching). In dark, the bleaching rate of ppR was very slow whereas illumination accelerated considerably the bleaching rate. Addition of azide accelerated the decay of the M-intermediate while its formation (decay of the L-intermediate) is not affected. The bleaching rate of ppR under illumination was decreased by addition of azide. Essentially no reactivity with hydroxylamine under illumination was observed in the case of D75N mutant which lacks the M-intermediate in its photocycle. Moreover, we provided illumination by flashes to ppR in the presence of varying concentrations of azide to measure the bleaching rate per one flash. A good correlation was obtained between the rate and the mean residence time, MRT, which was calculated from flash photolysis data of the M-decay. These findings reveal that water-soluble hydroxylamine reacts selectively with the M-intermediate and its implication was discussed.
KW - Bacteriorhodopsin
KW - Bleach of chromophore
KW - M-Intermediate
KW - Natronobacterium pharaonis
KW - Pharaonis sensory rhodopsin II
UR - http://www.scopus.com/inward/record.url?scp=0035801920&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0035801920&partnerID=8YFLogxK
U2 - 10.1016/S0005-2736(01)00380-7
DO - 10.1016/S0005-2736(01)00380-7
M3 - Article
C2 - 11513812
AN - SCOPUS:0035801920
VL - 1514
SP - 152
EP - 158
JO - Biochimica et Biophysica Acta - Biomembranes
JF - Biochimica et Biophysica Acta - Biomembranes
SN - 0005-2736
IS - 1
ER -