TY - JOUR
T1 - Rabbit muscle phosphofructokinase. I. Anomeric specificity; initial velocity kinetics
AU - Bar Tana, J.
AU - Cleland, W. W.
PY - 1974
Y1 - 1974
N2 - Initial velocity patterns have been obtained for rabbit muscle phosphofructokinase at pH 7.4, 25°, with 6 nucleotides as substrates, and also with 2,5 anhydro D mannitol 6 P and 2,5 anhydro D mannitol 1,6 P2 as substrate analogs. In the forward (MgNTP, fructose 6 P) direction most of the patterns were parallel or nearly so, but with MgITP and MgTCP there was clear convergence. In the reverse direction all patterns except for MgGDP were clearly intersecting. The mechanism must therefore be sequential. The good activity of the anhydromannitol analog, but the failure of L sorbose 6 P or 2,5 anhydro D glucitol 6 P prepared either chemically or enzymatically to act as a substrate suggests that the enzyme is specific both for the β anomers of fructose 6 P and fructose P2 and for the D configuration at carbon 5. The activity of fructose 1 P (presumably the β anomer) as a substrate is consistent with this view, as is the failure of L sorbose 1 P to act either as inhibitor or substrate.
AB - Initial velocity patterns have been obtained for rabbit muscle phosphofructokinase at pH 7.4, 25°, with 6 nucleotides as substrates, and also with 2,5 anhydro D mannitol 6 P and 2,5 anhydro D mannitol 1,6 P2 as substrate analogs. In the forward (MgNTP, fructose 6 P) direction most of the patterns were parallel or nearly so, but with MgITP and MgTCP there was clear convergence. In the reverse direction all patterns except for MgGDP were clearly intersecting. The mechanism must therefore be sequential. The good activity of the anhydromannitol analog, but the failure of L sorbose 6 P or 2,5 anhydro D glucitol 6 P prepared either chemically or enzymatically to act as a substrate suggests that the enzyme is specific both for the β anomers of fructose 6 P and fructose P2 and for the D configuration at carbon 5. The activity of fructose 1 P (presumably the β anomer) as a substrate is consistent with this view, as is the failure of L sorbose 1 P to act either as inhibitor or substrate.
UR - http://www.scopus.com/inward/record.url?scp=0015953849&partnerID=8YFLogxK
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C2 - 4273520
AN - SCOPUS:0015953849
SN - 0021-9258
VL - 249
SP - 1263
EP - 1270
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 4
ER -