Characterization of a monomeric phosphofructokinase from banana — role of magnesium on its regulation

Purification and characterization of pyrophosphate- and ATP-dependent phosphofructokinases from banana fruit

“…This indicates that banana PFK and PFP are quite susceptible to inactivation by phenols and tannins, which are particularly abundant in the unripe fruit. This provides a rationale for the previously reported low PFK activity of preclimacteric fruit, and unusual physical and kinetic properties described for banana fruit PFK (Nair and Darak 1981;Surendranathan and Nair 1989;Surendranathan et al 1990Surendranathan et al , 1992. Phenolic-and tanninscavenging compounds, or protease inhibitors, were not included in the extraction buffers used in the aforementioned studies.…”

“…In addition, some debate has centred around the maximal extractable activity of PFK during the transition of unripe to ripe bananas, which has been suggested to either increase (Salminen and Young 1975;Iyer et al 1989a;Ball et al 1991) or remain constant (Mertens et al 1987). Furthermore, in contrast to other plant PFKs (Plaxton 1996), banana PFK was reported to: (i) be insensitive to activation by Pi or inhibition by PEP (Surendranathan et al 1990), (ii) utilize ATP or ADP as a phosphoryl donor (Surendranathan and Nair 1989), and (iii) undergo subunit-dissociation (oligomer to monomer) upon fruit ripening (Iyer et al 1989a(Iyer et al , 1989bSurendranathan and Nair 1989). During these studies, the purification or kinetic characterization of PFP was not undertaken and, to our knowledge, has not been presented for banana fruit elsewhere.…”

Characterisation of the ATP‐dependent phosphofructokinase gene family from Arabidopsis thaliana

“…While PFP has been studied in detail, plant PFK has received only little attention. Besides extensive studies of Musa cavendishii PFKs [18][19][20][21][22], the enzyme was analysed in Daucus carota, Cucumis sativus, Solanum tuberosum, Ricinus communis, and Spinacia oleracea [23][24][25][26][27][28][29][30][31][32] (see Table 1 for details). Neither subunit composition nor the size of the protein was similar in all plant species tested.…”