1.1 Equilibrium constants
Enzyme
G6PI
Mass action ratio
[G6P]
[F6P]
[GA3P][DHAP]
[FDP]
[E4P][DHAP]
[S17DP]
Value
3.
Conditions
check
Reference
(Kahana, Lowry et al.
1960)
1.710-5 M
?
(Berthon, Kuchel et al.
1992)
5.310-6 M
?
(Berthon, Kuchel et al.
1992)
G6PDH (EC 1.1.1.49)
[6PGL][NADPH][H ]
[G6P][NADP ]
610-7 M
pH 6.4, no Mg2+, 28oC
(Glaser
1955)
and
Brown
6PGLase (EC 3.1.1.31)
[6PGO][H ]
[6PGL]
[Ru5P][NADPH][CO 2 ]
[6PGO][NADP  ]
[E4P][F6P]
[S7P][GA3P]
?
0.17 M
pH 7.0, no Mg2+, 37oC
(Villet
1969)
and
Dalziel
1.22
27oC, no pH reported
Aldolase
6PGDH (EC 1.1.1.44)
TA (EC 2.2.1.2)
1.05
0.370.02
TK (EC 2.2.1.1)
[F6P][GA3P]
[X5P][R5P]
1
11.9
29.71.1
Ribulose-5-P 3epimerase (EC 5.1.3.1)
[S7P][GA3P]
[X5P][R5P]
[X5P][R5P]
[S7P][GA3P]
0.95
[R5P][F6P]
[S7P][E4P]
18.71.2
[X5P]
[Ru5P]
1.5
1.4
0.480.08
1.820.02
Ribose-5-P isomerase
(EC 5.3.1.6)
[R5P]
[Ru5P]
3.0
3.0
(Horecker
and
Smyrniotis 1955)
pH 7.4, no Mg2+, 37oC
(Venkataraman
and
Racker 1961)
pH 7.0, 1 mM free (Casazza and Veech
Mg2+, I= 0.25 M (adj. 1986)
w/ KCl), 38oC
pH=?,
T=?, (Horecker, Smyrniotis
[Mg2+]=1.66 mM
et al. 1956)
pH 7.6, 1 mM total (Datta and Racker
Mg2+, 25oC
1961)
pH 7.0, 1 mM free (Casazza and Veech
Mg2+, I= 0.25 M (adj. 1986)
w/ KCl), 38oC
pH=?, 1 mM total (Datta and Racker
Mg2+, 25oC
1961)
pH 7.0, 1 mM free
Mg2+, I= 0.25 M (adj.
w/ KCl), 38oC
pH 7.0, 1 mM free
Mg2+, I= 0.25 M (adj.
w/ KCl), 38oC
Conditions?
pH 7.5, no Mg2+, 37oC
(Casazza
1986)
and
Veech
(Casazza
1986)
and
Veech
(Hurwitz 1962)
(Ashwell and Hickman
1957)
pH 7.0, 1 mM free (Casazza and Veech
Mg2+, I= 0.25 M (adj. 1986)
w/ KCl), 38oC
pH 7.2, 33oC
(Dische and Shigeura
1957)
Conditions?
(Tabachnick, Srere et
al. 1958)
3.3
1.200.02
TPI
GSSGR
1.06109
[NADP  ][GSH]2
[NADPH][GSSG][H  ]
37oC, pH=?
(Dobrogosz
Demoss 1963)
pH 7.0, 1 mM free (Casazza and
Mg2+, I= 0.25 M (adj. 1986)
w/ KCl), 38oC
and
Veech
pH 6.8, I= 0.33 M, (Scott, Duncan et al.
40oC
1963)
References
Kahana, S. E., O. H. Lowry, et al. (1960). "KINETICS OF PHOSPHOGLUCOISOMERASE." Journal Of
Biological Chemistry 235(8): 2178-2184.
Berthon, H. A., W. A. Bubb, et al. (1993). "13C n.m.r. isotopomer and computer-simulation studies of the
non-oxidative pentose phosphate pathway of human erythrocytes." Biochemical Journal 296 ( Pt 2): 379387.
Glaser, L. and D. H. Brown (1955). "PURIFICATION AND PROPERTIES OF D-GLUCOSE-6PHOSPHATE DEHYDROGENASE." Journal Of Biological Chemistry 216(1): 67-79.
Villet, R. H. and K. Dalziel (1969). "The nature of the carbon dioxide substrate and equilibrium constant
of the 6-phosphogluconate dehydrogenase reaction." Biochemical Journal 115(4): 633-638.
Horecker, B. L. and P. Z. Smyrniotis (1955). "PURIFICATION AND PROPERTIES OF YEAST
TRANSALDOLASE." Journal Of Biological Chemistry 212(2): 811-825.
Datta, A. G. and E. Racker (1961). "MECHANISM OF ACTION OF TRANSKETOLASE .1.
PROPERTIES OF CRYSTALLINE YEAST ENZYME." Journal Of Biological Chemistry 236(3): 617623.
Casazza, J. P. and R. L. Veech (1986). "The interdependence of glycolytic and pentose cycle
intermediates in ad libitum fed rats." Journal Of Biological Chemistry 261(2): 690-698.
Hurwitz, J. (1962). "D-XYLULOSE 5-PHOSPHATE-3-EPIMERASE." Methods In Enzymology 5: 247257.
Ashwell, G. and J. Hickman (1957). "ENZYMATIC FORMATION OF XYLULOSE 5-PHOSPHATE
FROM RIBOSE 5- PHOSPHATE IN SPLEEN." Journal Of Biological Chemistry 226(1): 65-76.
Dische, Z. and H. Shigeura (1957). "MECHANISMS IN THE INTERCONVERSION OF RIBOSE-5PHOSPHATE AND HEXOSE-6-PHOSPHATE IN HUMAN BLOOD .1. ISOMERIZATION OF
RIBOSE- 5-PHOSPHATE IN HUMAN HEMOLYSATES." Biochimica Et Biophysica Acta 24(1): 8799.
Tabachnick, M., P. A. Srere, et al. (1958). "THE OXIDATIVE PENTOSE PHOSPHATE CYCLE .3.
THE INTERCONVERSION OF RIBOSE 5-PHOSPHATE, RIBULOSE 5-PHOSPHATE AND
XYLULOSE 5- PHOSPHATE." Archives Of Biochemistry And Biophysics 74(2): 315-325.
Dobrogosz, W. J. and R. D. Demoss (1963). "STUDIES ON REGULATION OF
RIBOSEPHOSPHATEISOMERASE ACTIVITY IN PEDIOCOCCUS PENTOSACEUS." Biochimica Et
Biophysica Acta 77(4): 629-&.
Scott, E. M., I. W. Duncan, et al. (1963). "Purification and properties fo glutathione reductase of human
erythrocytes." Journal Of Biological Chemistry 238: 3928-3933.