Ln. Bloksberg et Ci. Kado, BROAD ALDEHYDE SPECIFICITY, INCLUDING TOMATO ALDEHYDES, BY RECOMBINANT LUCIFERASE FROM PHOTOBACTERIUM, Plant physiology and biochemistry, 34(1), 1996, pp. 127-131
Bacterial luciferase (Lux) is a light producing flavoenzyme encoded by
the luxA and luxB genes of the six gene lux operon of Photobacterium
fischeri and Vibrio harveyi. Luciferase produces light by the oxidatio
n of aldehyde in the presence of reduced flavin and oxygen. A simple a
nd highly sensitive bioassay, employing a recombinant fusion protein c
omprised of LuxA and LuxB subunits containing an 81 base pair spacer s
equence for optimum activity in Escherichia coli was used to measure t
he effects of different aldehydes as substrates for the recombinant lu
ciferase activity. We examined a range of aliphatic aldehydes, and fou
nd that the recombinant luciferase utilizes any linear aliphatic aldeh
yde from 1 to 12 carbons in length, including several branched forms.
The recombinant luciferase exhibited increased efficiency of substrate
binding and product formation with increasing aldehyde length. Natura
lly occurring endogenous aldehydes in tomato plants measured by our bi
oassay system, demonstrated that the concentrations of aldehyde are or
gan specific and reflect the stage of development. The tomato fruit wa
s found to accumulate free aldehydes as it ripens, confirming previous
chemical analyses on ripening fruits.