Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:4.1.2.13 (
aldolase
)
3,461
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Cytosolic fructose-1,6-P(2) (FBP)
aldolase
(ALD(c)) from germinated mung beans has been purified 1078-fold to electrophoretic homogeneity and a final specific activity of 15.1 micromol FBP cleaved/min per mg of protein. SDS-PAGE of the final preparation revealed a single protein-staining band of 40 kDa that cross-reacted strongly with rabbit anti-(carrot ALD(c))-IgG. The enzyme's native M(r) was determined by gel filtration chromatography to be 160 kDa, indicating a homotetrameric quaternary structure. This ALD is a class I ALD, since EDTA or Mg(2+) had no effect on its activity, and was relatively heat-stable losing 0-25% of its activity when incubated for 5 min at 55-65 degrees C. It demonstrated: (i) a temperature coefficient (Q(10)) of 1.7; (ii) an activation energy of 9.2 kcal/mol active site; and (iii) a broad pH-activity optima of 7.5. Mung bean ALD(c) is bifunctional for FBP and sedoheptulose-1,7-P(2) (K(m) approximately 17 microM for both substrates). ATP, ADP, AMP and ribose-5-P exerted inhibitory effects on the activity of the purified enzyme.
Ribose
-5-P, ADP and AMP functioned as competitive inhibitors (K(i) values=2.2, 3.1 and 7.5mM, respectively). By contrast, the addition of 2mM ATP: (i) reduced V(max) by about 2-fold, (ii) increased K(m)(FBP) by about 4-fold, and (iii) shifted the FBP saturation kinetic plot from hyperbolic to sigmoidal (h=1.0 and 2.6 in the absence and presence of 2mM ATP, respectively). Potent feedback inhibition of ALD(c) by ATP is suggested to help balance cellular ATP demands with the control of cytosolic glycolysis and respiration in germinating mung beans.
...
PMID:Purification and characterization of an allosteric fructose-1,6-bisphosphate aldolase from germinating mung beans (Vigna radiata). 1589 64
Ribose
methylation is among the most ubiquitous modifications found in RNA. 2'-
O
-methyluridine is found in rRNA, snRNA, snoRNA and tRNA of
Archaea
,
Bacteria
, and
Eukaryota
. Moreover, 2'-
O
-methylribonucleosides are promising starting materials for the production of nucleic acid-based drugs. Despite the countless possibilities of practical use for the metabolic enzymes associated with methylated nucleosides, there are very few reports regarding the metabolic fate and enzymes involved in the metabolism of 2'-
O
-alkyl nucleosides. The presented work focuses on the cellular degradation of 2'-
O
-methyluridine. A novel enzyme was found using a screening strategy that employs
Escherichia coli
uracil auxotroph and the metagenomic libraries. A 2'-
O
-methyluridine hydrolase (RK9NH) has been identified together with an
aldolase
(RK9DPA)-forming a part of a probable gene cluster that is involved in the degradation of 2'-
O
-methylated nucleosides. The RK9NH is functional in
E. coli
uracil auxotroph and in vitro. The RK9NH nucleoside hydrolase could be engineered to enzymatically produce 2'-
O
-methylated nucleosides that are of great demand as raw materials for production of nucleic acid-based drugs. Moreover, RK9NH nucleoside hydrolase converts 5-fluorouridine, 5-fluoro-2'-deoxyuridine and 5-fluoro-2'-
O
-methyluridine into 5-fluorouracil, which suggests it could be employed in cancer therapy.
...
PMID:Identification of a 2'-
O
-Methyluridine Nucleoside Hydrolase Using the Metagenomic Libraries. 3040 65
