Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.1.2.13 (aldolase)
 3,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An X-ray crystallographic structure determination has been carried out on 2-keto-3-deoxy-6-phosphogluconic (KDPG) aldolase at 3.5-A resolution using the multiple isomorphous replacement method with three heavy atom derivatives along with anomalous dispersion contributions from two of the derivatives. Crystals grown from ammonium sulfate-phosphate buffered (pH 3.5) solutions were: cubic, a= 103.40 (4) A, space group P213. KDPG aldolase consists of trimeric heterologous assemblages utilizing crystallographic threefold symmetry. The overall profile of the oligomeric structure viewed down the threefold axis resembles that of a ship propeller while the subunits are approximate irregular oblate ellipsoids (25 X 45 X 45 A). The folding of most of the polypeptide chain was traced unambiguously. Secondary structural features consist of nine helical regions (75 residues, 35%) and a pair of two parallel chains. The subunit contains a long empty channel which is about 9 X 9 X 30 A with one of the pair of parallel chains forming part of the wall. Three mercury binding sites are located in this channel. These might correspond to the two readily accessible and one of the two buried cysteine residues of each subunit. The channel terminates with another cavity of about 8 X 10 X 25 A near the surface of the oligomeric structure. The regions of the subunits near the threefold axis are characterized by a high degree of secondary structural organization and these make close intersubunit contacts. Quarternary interactions are due mainly to side-chain interactions of helices.
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PMID:The folding and quaternary structure of trimeric 2-keto-3-deoxy-6-phosphogluconic aldolase at 3.5-A resolution. 97 67

In Saccharomyces cerevisiae, the HGS2-1 allele confers sensitivities to inorganis mercury (Ono and Sakamoto 1985) and to excess fermentable sugars such as glucose (Sakamoto et al. 1985); exogenous tyrosine antagonizes both inorganic mercury and excess glucose. In this study, the inorganic mercury sensitive strain has been shown to have about twice more glucose-1,6-bisphosphate and slightly less pyruvate than the normal strains, suggesting that the inorganic mercury sensitive strain has the reduced aldolase activity. It has been also shown that the growth retarded cells accumulate trehalose, by which the lower level of glucose-6-phosphate in the inorganic mercury sensitive strain is accounted for, and that inorganic mercury, presumably excess glucose also, causes growth inhibition via depletion of cellular tyrosine. The mechanism how cellular tyrosine is depleted by inorganic mercury or excess glucose is accounted for by the facts that (1) the tyrosine uptake activity is decreased with increase of glucose concentration in growth medium, (2) HGS2-1 enhances the effect of glucose on the tyrosine uptake activity, and (3) inorganic mercury inhibits the tyrosine uptake system by binding to its SH-group(s). Thus, it is concluded that the role of tyrosine is not to detoxify inorganic mercury nor excess fermentable sugars but simply to counteract depletion of cellular tyrosine induced by them.
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PMID:Saccharomyces cerevisiae strains sensitive to inorganic mercury. III. Tyrosine uptake. 332 70

A new analytical approach has been applied to the determination and characterization of mercury-accessible -SH groups in pure native protein samples (ovalbumin, hemoglobin, glyceraldehyde-3-phosphate dehydrogenase, aldolase, pyruvate kinase, hexokinase, lactate dehydrogenase, alcohol dehydrogenase, creatine phosphokinase, lysozyme, and cytochrome c). The method is based on the selective reduction of Hg(II) in the presence of Hg(II)-thiol complexes with alkaline sodium tetrahydroborate, to give Hg(0) in a continuous flow reaction system coupled with atomic fluorescence spectrometric (AFS) detection. The method is fast and specific and allows one to work with nanomole amounts of a single protein without any preliminary incubation and without any separation of Hg(II) from thiol-complexed mercury. The meaning of the results obtained in the determination of the accessible -SH groups in native proteins by using chemical probes is discussed.
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PMID:Application of mercury cold vapor atomic fluorescence spectrometry to the characterization of mercury-accessible -SH groups in native proteins. 1052 12

Hydrophobic interaction chromatography coupled online with chemical vapour atomic fluorescence spectrometry (HIC-CVGAFS) has been optimized for the analysis of thiolic proteins in denaturing conditions. Proteins are pre-column simultaneously denatured and derivatized in phosphate buffer solution containing 8.0moldm(-3) urea and p-hydroxymercurybenzoate (PHMB) and the derivatized denatured proteins are separated on a silica HIC Eichrom Propyl column in the presence of 8.0M urea in the mobile phase. Post-column online reaction of derivatized denatured proteins with bromine, generated in situ by KBr/KBrO(3) in HCl medium, allowed the fast conversion of the uncomplexed PHMB and of the PHMB bound to proteins to inorganic mercury also in presence of urea. Hg(2+), present in solution as Hg(2+)-urea complex, is selectively detected by AFS in a Ar/H(2) miniaturized flame after sodium borohydride reduction to Hg. Under optimized conditions, online bromine treatment gives a 100+/-2% recovery of both free and protein-complexed PHMB. Denatured glyceraldehyde-3-phosphate dehydrogenase, aldolase, lactate dehydrogenase, trioso phosphate isomerase and beta-lactoglobulin have been examined. As the sensitivity and limit of detection of proteins in the HIC-CVGAFS apparatus depends on number of SH groups reacting with PHMB, the denaturation process, which increases the number of PHMB-reactive thiolic groups in proteins, improves the analytical performances of the described system in protein analysis. The detection limit for the denatured proteins examined was found in the range of 10(-10)-10(-12)moldm(-3), depending on the considered protein, with linear calibration curves spanning over four decades of concentration.
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PMID:Hydrophobic interaction chromatography coupled with atomic fluorescence spectrometric detection Effect of the denaturation on the determination of thiolic proteins. 1896 44

A monolithic wide-pore silica column was newly prepared for protein separation. The wide distribution of the pore sizes of monolithic columns was evaluated by mercury porosimetry. This column, as well as the conventional monolithic column, shows high permeability in the chromatographic separation of low-molecular-sized substances. In higher-molecular-sized protein separation, the wide-pore monolithic silica column shows better performance than that of the conventional monolithic column. Under optimized conditions, five different proteins--ribonuclease A, albumin, aldolase, catalase, and ferritin--were baseline-separated within 3 min, which is faster than that using the particle-packed columns. In addition, the monolithic wide-pore silica column could also be prepared in fused silica capillary (600 mm long, 0.2 mm i.d.) for highly efficient protein separation. The peak capacity of the wide-pore monolithic silica capillary column is estimated to be approximately 300 in the case of protein separation, which is a characteristic performance.
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PMID:Performance of wide-pore monolithic silica column in protein separation. 1957 77