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Pyrophosphate‐dependent phosphofructokinase from pollen: properties and possible roles in sugar metabolism
Author(s) -
Nakamura Norio,
Suzuki Yoshiomi,
Suzuki Hiroshi
Publication year - 1992
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1992.tb02178.x
Subject(s) - phosphofructokinase , pollen , pyrophosphate , sugar , biochemistry , biology , camellia , glycolysis , metabolism , botany , enzyme
To evaluate the role of pyrophosphate‐dependent phosphofructokinase (PFP. EC 2.7.1.90) in the sugar metabolism of pollen. its occurrence and properties were studied in pollen grains of several plants including camellia ( Camellia japonica L.). In all pollen samples, PFP was strongly activated by fructose‐2,6‐bisphosphate (F2,6BP), and the activity of F2,6BP‐activated PFP was higher than that of phosphofructokinase (PFK. EC 2.7.1.11). PFP partially purified from camellia pollen required Mg 2+ for activity with an optimum at 1 m M . and was almost unaflected by a variety of metabolites at 1 m M . Its molecular mass was around 220 kDa, and apparent K m values for F6P, PP i . F1, 6BP and P i were 294, 4, 20 and 580 u M , respectively. The levels of F2.6BP. PP i and F6P in camellia pollen were sufficent to support the forward reaction by PFP, and PFP, was 20‐ to 40‐fold more active than PFK during pollen growth. These results suggest that pollen PFP plays a role in glycolysis but not gluconeogenesis. and the possible relevance of this to pollen tube growth is discussed.