Keima-Red
- large Storkes shift
- for use with simultaneous multicolor imaging
- for use with single laser line FCCS
CoralHue® dimeric Keima-Red (dKeima-Red) and CoralHue® monomeric Keima-Red (mKeima-Red) are red fluorescent proteins with extremely large Stokes shift. They absorb light maximally at 440 nm and emit red light at 616 nm and 620 nm, respectively. There are no other fluorescent proteins with this unique fluorescence. Because of this charecteristic, they are excited by a very short wavelength but emit a long wavelength. Keima-Red is named after a shogi (Japanese chess) piece. Keima(
) is a shogi piece that can move in the hopping manner, similar to the knight in the game of chess.
The large Storkes shift property of Keima-Red allows effective applications such as for single wavelength excitation simultaneous multi-color imaging and single laser line FCCS.
Fluorescent properties
Download mKeima-Red spectra Ex, Em (txt.)
Download dKeima-Red spectra Ex, Em (txt.)
| CHARACTERISTIC | dKeima-Red | mKeima-Red |
|---|---|---|
| Oligomerization | Dimer | Monomer |
| Number of amino acid | 222 | 222 |
| Excit./Emiss. maxima (nm) | 440/616 | 440/620 |
| Molar extinction coefficient (M-1cm-1) | 24,600 (440 nm) | 14,400 (440 nm) |
| Fluorescence quantum yield | 0.31 | 0.24 |
| Brightness*1 | 7.6 | 3.5 |
| pH sensitivity | pKa=6.5 | pKa=6.5 |
| Cytotoxicity*2 | No | No |
*1Brightness: Molar Extinction Coefficient ×Fluorescence Quantum Yield / 1000
*2Toxicity when expressed in HeLa cells
Performance and use:
dKeima-Red and mKeima-Red are easily expressed in a wide range of organisms. dKeima-Red and mKeima-Red has been demonstrated in the nucleoplasm, plasma membrane, and mitochondria targeting signal models.
mKeima-Red use in multicolor labeling of mammalian cells.
An image of the HeLa cell with mKO1 localized on the plasma membrane (red), mAG1 in the endoplasmic reticulum (green) and mKeima-Red in the mitochondria (blue).
Filters and mirrors
mKeima-Red Ex : 440AF21, Em : 610ALP, DM : 590DRLP
mAG1 Ex : BP460-480HQ, Em : BA495-540HQ, DM : DM485
mKO1 Ex : BP520-540HQ, Em : BA555-600HQ, DM : DM545HQ
Simultaneous four-color imaging of subcellular structures in a Vero cell using a single laser line (458 nm).
Normalized excitation and emission spectra of SECFP, mMiCy, Venus and mKeima (a). An image of the Vero cell with SECFP localized on the plasma membrane (cyan), mMiCy in the endoplasmic reticulum (green), YFP along the microtubules (red) and mKeima in the mitochondria (purple) (b) . The image was created by merging the following images, which were obtained using spectral imaging: SECFP-pm (c), mMiCy-er (d), Venus-mt (e) and mKeima-mit (f).
Spectra imaging with a single laser line at 458 nm (Ar ion laser) was performed using the 32 channels of the LSM 510 META system (Carl Zeiss).
Images were kindly provided by Takako Kogure, Atsushi Miyawaki (Laboratory for Cell Function and Dynamics , BSI, RIKEN).
Recommended antibodies
CoralHue® dKeima-Red and mKeima-Red can be recognized using antibodies as shown below.
WB: Western blotting, IP: Immunoprecipitation
References
A fluorescent variant of a protein from the stony coral Montipora facilitates dual-color single-laser fluorescence cross-correlation spectroscopy.
Kogure T, Karasawa S, Araki T, Saito K, Kinjo M, Miyawaki A.
Nat Biotechnol. (2006) 24(5):577-81.
PMID: 16648840
Two-photon dual-color imaging using fluorescent proteins.
Kawano H, Kogure T, Abe Y, Mizuno H, Miyawaki A.
Nat Methods. (2008) 5(5):373-4.
PMID: 18446153
Fluorescence imaging using a fluorescent protein with a large Stokes shift.
Kogure T, Kawano H, Abe Y, Miyawaki A.
Methods. (2008) 45(3):223-6.
PMID: 18586106
Intranuclear fluorescence resonance energy transfer analysis of plasmid DNA decondensation from nonviral gene carriers.
Matsumoto Y, Itaka K, Yamasoba T, Kataoka K.
J Gene Med. (2009) 11(7):615-23.
PMID: 19396931
Reverse pH-dependence of chromophore protonation explains the large Stokes shift of the red fluorescent protein mKeima.
Violot S, Carpentier P, Blanchoin L, Bourgeois D.
J Am Chem Soc. (2009) 131(30):10356-7.
PMID: 19722611
Excited state proton transfer in the red fluorescent protein mKeima.
Henderson JN, Osborn MF, Koon N, Gepshtein R, Huppert D, Remington SJ.
J Am Chem Soc. (2009) 131(37):13212-3.
PMID: 19708654
