Maj. Parry et al., The localisation of 2-carboxy-D-arabinitol 1-phosphate and inhibition of Rubisco in leaves of Phaseolus vulgaris L., FEBS LETTER, 444(1), 1999, pp. 106-110
A recent controversial report suggests that the nocturnal inhibitor of Rubi
sco, 2-carboxy-D-arabinitol 1-phosphate (CA1P), does not bind to Rubisco in
vivo and therefore that CA1P has no physiological relevance to photosynthe
tic regulation. It is now proved that a direct rapid assay can be used to d
istinguish between Rubisco-bound and free CA1P, as postulated in the contro
versial report. Application of this direct assay demonstrates that CA1P is
bound to Rubisco in vivo in dark-adapted leaves. Furthermore, CA1P is shown
to be in the chloroplasts of mesophyll cells, Thus, CA1P does play a physi
ological role in the regulation of Rubisco, (C) 1999 Federation of European
Biochemical Societies.