Molecular and catalytic properties of aldolase C

Model of 2,3-bisphosphoglycerate metabolism in the human erythrocyte based on detailed enzyme kinetic equations: equations and parameter refinement

“…(A4)-(A6), where The rate constants that yielded steady-state parameters closest to the literature values were : (M − 1 :s − 1 ), k 1 l 1.18i10 7 , k 4 l 6.5i10 6 , k 6 l 6.62i10 6 , k 7 l 1i10 9 ; (s − 1 ), k 2 l 234, k 3 l 995, k 5 l 73, and k 8 l 1.5i10 6 . Notes : a [54], human erythrocyte ; b [55], human erythrocyte ; c [56], rabbit muscle ; d [57], rabbit muscle ; e [58], rabbit muscle ; f [59,60] ; g [61], pH 7.0, 35 mC; h k cat,f was calculated from the specific activity of the purified (8000i) human erythrocyte enzyme (16.1 units/mg at pH 8.0, 30 mC ; [54]) adjusted to 37 mC by multiplying by the temperature correction factor 1.59 [62] ; Ald is reported to be a tetramer of total M r 158 000 [54] ; i the specific activity of the reverse reaction in rabbit muscle was found to be 3.45 times that of the forward reaction, at 25 mC [57] ; j the concentration of GPI in human erythrocytes, e o , was estimated from the measured human erythrocyte activity (1050 units/litre of erythrocytes, pH 7.6, 37 mC ; [62]) adjusted to pH 7.2 with eqn. (A2) and the value of k cat,f .…”

The crystal structure of fructose‐1,6‐bisphosphate aldolase fromDrosophila melanogaster at 2.5A˚resolution

“…It shows a similar closed conformation of the C-terminal arm as in DALD. The FBP/FIP activity ratio in muscle type aldolases is 50-100 while for the liver type aldolases this value is 1-2 [3]. For DALD the corresponding ratio is 20 [24].…”

“…FBP aldolase from Drosophila melanogaster (strain Sevelen, wild type, pupea) forms a Schiff base between the substrate and a lysyl residue [1] and belongs therefore to the class I aldolases [2]. Contrary to class I the class II aldolases use a divalent metal ion as cofactor [3]. The vertebrate aldolases (class I) comprise three isozymes.…”

“…The vertebrate aldolases (class I) comprise three isozymes. They refer to A (muscle), B (liver) and C (brain) depending on the tissue from which they are isolated [3]. The A and C form show a higher substrate specificity for FBP over fructose-l-phosphate (F1P), while the liver isozyme has no such preference.…”

Reappearance of aldolase C in rat liver during compensatory regeneration after partial hepatectomy

“…The technique of Penhoet, Kochman and Rutter [7] was used for the purification of the three isozy mes A, B and C of aldolase from extracts of muscle, liver and brain respectively. 76 2.3.…”