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. 2017 Oct 20;7:13648. doi: 10.1038/s41598-017-14037-0

Table 1.

Spectral and Kinetic Constants of Truncation and Point Mutants of Arabidopsis PhyB.

Mutationa Absorption maximab (nm) Photoconversion ratec,d,e (min−1) Therm revc,d,f (x1000 min−1)
Pr Pfr Pr ⇒ Pfr Pfr ⇒ Pr Pfr ⇒ Pr
Domain Truncations
PΦB
1–450 658 707 0.72g 0.11 (±0.02) 10.5 (±0.1)
1–624 664 724 0.98 (±0.03) 2.45 (±0.04) 7.91 (±0.02)
1–908h 665 724 k1 2.1 (±0.3) 2.6 (±0.2) 320 (±20)
k2 0.47 (±0.05) 34 (±3)
FLh,i 664 725 k1 1.1 410
k2 0.12 40
PCB
1–450 643 693 1.04 (±0.05) 0.38 (±0.02) 38.4 ( ± 0.1)
1–624 651 714 1.35 (±0.04) 3.52 (±0.03) 0.52 (±0.01)
1–908 651 714 1.20 (±0.08) 3.52 (±0.06) 29.9 (±0.3)
NTE Truncations
10–624 665 724 0.86 (±0.04) 2.43 (±0.01) 9.54 (±0.02)
20–624 665 724 0.82 (±0.09) 2.52 (±0.05) 10.1 (±0.1)
30–624 665 724 0.84 (±0.03) 2.54 (±0.07) 7.7 (±0.5)
41–624 665 725 0.88 (±0.03) 2.60 (±0.06) 6.50 (±0.02)
46–624 666 725 10.8 (±0.1)
51–624 664 723 1.1 (±0.1) 2.53 (±0.06) 16.2 (±0.1)
55–624 665 724 14.9 (±0.1)
56–624 665 723 32.3 (±0.1)
57–624 665 722 0.97 (±0.05) 2.35 (±0.09) 50.1 (±0.1)
59–624 664 719 91.8 (±0.3)
60–624 665 720 1.09 (±0.02) 2.39 (±0.06) 85 (±1)
65–624 666 717 1.18 (±0.09) 143 (±1)
70–624 665 717 1.05 (±0.06) 2.28 (±0.03) 146 (±1)
80–624 664 717 1.17 (±0.03) 2.3 (±0.1) 169 (±1)
90–624 664 717 1.3g 2.5g 163 (±1)
100–624 664 717 0.99 (±0.05) 2.2 (±0.2) 134 (±1)
PSM Point Mutants
S55A,K56A 666 725 16.3 (±0.1)
Q59A,Q60A 666 721 35.5 (±0.1)
Y61A,T62A 665 725 7.53 (±0.01)

aData were collected from PhyB containing the indicated residues after removal of the N-terminal 6His-TEV tag.

bMaxima of the Q absorption band. Pfr maxima were identified from difference spectra generated by subtracting red-irradiated from dark-adapted samples.

cCalculated from the global fit of absorption at 640 nm, 650 nm, 660 nm, 670 nm, 700 nm, 710 nm, 720 nm, 730 nm, and 740 nm as a function of time using the equation: Abs = ΔAbstotal•exp(−k•Time) + Absinitial.

dValues in parentheses represent the average of three technical replicates (±SD).

eFluence rate was calibrated to 12 μmol•m−2•s−1 at the intersecting spectrophotometric light path.

fFluence rate was calibrated to a nominal 0.465 μmol•m−2•s−1 for each measurement.

gAverage of two technical replicates.

hPr ⇒ Pfr photoconversion, Pfr ⇒ Pr photoconversion, and/or thermal reversion were expressed as the sum of two exponentials using the equation: Abs = ΔAbstotal1•exp(−k1*Time) + ΔAbstotal2•exp(−k2•Time) + Absinitial.

iData were collected from a single sample.