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

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Query: EC:4.1.2.13 (aldolase)
3,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Glyceraldehyde 3-phosphate dehydrogenase and 3-phosphoglycerate kinase are, together with some other enzymes, present on the surface of intact Ehrlich tumor cells. Aldolase, on the contrary, represents cytoplasmic enzymes not present at all on the external surface, provided 2.5 percent of bovine albumin is included in the isotonic assay medium. A flux of aldolase from the cell interior to the cell exterior could be demonstrated in the absence of albumin. Therefore, any enzymatic activity monitored when keeping the Ehrlich tumor cells in the isotonic assay medium containing 2.5 percent albumin was considered to be primarily related to the outside of the plasma membrane. Of the total glyceraldehyde 3-phosphate dehydrogenase, 0.7 percent was located on the outer surface of the tumor cell, while the corresponding figure for 3-phospoglycerate kinase was 2.7 percent. Eighty percent of this surface-located 3-phosphoglycerate kinase was released into the assay medium during incubation, while the release of glyceraldehyde 3-phosphate dehydrogenase, at the same time, was minimal. A plasma membrane preparation of Ehrlich cells, mainly consisting of vesicles, showed the presence of 3-phosphoglycerate kinase but the absence of glyceraldehyde 3-phosphate dehydrogenase. Because of the vesicular nature of the membrane preparation, it was assumed that only one side of the membrane was exposed during assay. The specific binding properties of the two enzymes to the plasma membrane, as well as possible differences in their intramembranous location, are discussed.
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PMID:Enzyme activities at the surface of intact Ehrlich tumor cells with albumin in the isotonic assay medium. 113 21

The peptides released during the limited tryptic proteolysis of rabbit muscle aldolase (Biszku et al., 1973) were located in the primary structure. The pattern of peptide liberation, peptide bond splitting and activity decrease in compatible with two structural models for the truncated tetrameric product, named aldolase-T. According to the more probable model aldolase-T has the structure A+A+B++B++. Subunits B++ are deprived of the segments comprising residues 1-27, 42-71 and 306-364 of the intact enzyme and are inactive. The fragment comprising residues 28-41 is non-covalently attached to these subunits. Subunits A+ are depleted only of peptides 1-27 and 324-332 and retain 70% activity. In these subunits the fragment comprising residue 333-364 remains non-covalently bound. The molecular weights of the truncated subunits, determined with polyacrylamide-gel electrophoresis in the presence of sodium dodecylsulfate support the above conclusions. Aldolase-T can be reversibly denatured at pH 2 or in 4 M urea. The recovery of enzymatic activity after decreasing urea or acid concentration indicates the non-covalent rebinding of fragment 333-364. This fragment is named the "T-peptide" of trypsin-treated aldolase. It is suggested that segments 1-27 and 324-364 are not necessary for the renaturation process. Since aldolase-T is a tetramer it seems that large parts of the N- and C-terminal regions of the enzyme are not involved in the intersubunit interactions. The C-terminal region of aldolase, starting around residue 324, appears to be necessary to the structure of the active site. In contrast to this, the N-terminal region up to residue 27 and probably to residue 60, is not part of the active center.
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PMID:Some structural features of rabbit muscle aldolase as derived from its limited proteolysis. 121 Nov 2

Electronmicroscopic studies have been made on the structure of liposomes obtained by the method of Bangham [13] with subsequent ultrasonic desintegration. The effect of muscle aldolase on the structure of liposomes was also investigated. Parallel studies were made on the effect of storage of liposomes upon the activity of aldolase. It was shown that liposomes obtained from chromatographically pure egg lecithin present discrete partially aggregated bodies, 1.000-3.000 A in size, composed by concentric layers, which have a dimension of approximately 40 A and periodicity of about 70 A. Interaction of these particles with the protein results into their desintegration and enlargement, this process being accompanied by the formation of a "fringe" at the edge of the particles. Aldolase activity in these systems in higher than in control. During storage of phosphatide-aqueous system, obtained by the metod of Bungenberg de Jong, activation of aldolase is gradually replaced by its inactivation.
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PMID:[Studies on the activity of aldolase from rabbit muscles in the presence of liposomes]. 121 9

Aldolase is a trace protein in isolated human red cell membrane preparations. Following total elution of the endogenous enzyme by a saline wash, the interaction of this membrane with rabbit muscle aldolase was studied. At saturation, exogenous aldolase constituted over 40% of the repleted membrane protein. Scatchard analysis revealed two classes of sites, each numbering approximately 7 X 10(5) per ghost. Specificity was suggested by the exclusive binding of the enzyme to the membrane's inner (cytoplasmic) surface. Furthermore, milimolar levels of fructose 1,6-bisphosphate eluted the enzyme from ghosts, while fructose 6-phosphate and NADH (a metabolite which elutes human erythrocyte glyceraldehyde-3-phosphate dehydrogenase (G3PD) from its binding site) were ineffectuve. Removing peripheral membrane proteins with EDTA and lithium 3,5-diiodosalicylate did not diminish the binding capacity of the membranes. An aldolase-band 3 complex, dissociable by high ionic strength or fructose 1,6-bisphosphate treatment, was demonstrated in Triton X-100 extracts of repleted membranes by rate zonal sedimentation analysis on sucrose gradients. We conclude that the association of rabbit muscle aldolase with isolated human erythrocyte membranes reflects its specific binding to band 3 at the cytoplasmic surface, as is also true of G3PD.
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PMID:Binding of rabbit muscle aldolase to band 3, the predominant polypeptide of the human erythrocyte membrane. 125 46

A study was made of the blood serum proteins, thiol groups, aldolase activity, testosterone content in rabbits under conditions of insufficiency of the prostate gland caused by its suturing. It was revealed that at the late postoperative periods there was an increase in the blood serum proteins of albumin fraction, and a reduction of the thiol group level (SH-free, masked and disulfide). Aldolase activity increased at the early periods and then sharply fell. The incretory function of the testes was disturbed.
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PMID:[Blood proteins, thiol group metabolism and testosterone content in prostatic dysfunction]. 127 54

We investigated three aldolase isozymes (aldolase A, B, and C) in human lung cancer by using an indirect peroxidase labeled antibody method. We used 27 tissue samples obtained at surgical operations which were fixed in periodate-lysine-4% paraformaldehyde (PLP) solution, and embedded in optimum cutting temperature (OCT) compound. They were 11 adenocarcinomas, 9 squamous cell carcinomas, 3 large cell carcinomas, 3 small cell carcinomas, and 1 adenosquamous carcinoma. Aldolase A and C expressed intensely positive stainings in the cytoplasm of cancer cells compared with normal lung tissues, and its positivities were 81% respectively. However, Aldolase B showed almost negative staining, and its positivities were only 41%. These rates had no relation to the histological types or pathological stages of lung cancers, and suggested that human lung cancer contained increased levels of aldolase A, and C.
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PMID:[An immunohistochemical study on three aldolase isozymes in human lung cancer]. 131 19

We report the construction of an inducible, high-copy plasmid for the expression of foreign proteins in Escherichia coli. This plasmid, pPB1, combines the trc promoter, beta-galactosidase translation start site, and polylinker of pKK233-2 with the origin of replication region of pUC19. Replacement of the origin of replication of pKK233-2 results in a threefold increase in plasmid copy number of pPB1 compared with pKK233-2. Subclones of the cDNA for rabbit muscle fructose-1,6-bisphosphate aldolase (E.C. 4.1.2.13) in the two expression plasmids exhibit a comparable difference in copy number. An increase in protein expression measured by SDS-PAGE and aldolase specific activities reflects the increased copy number. Specific activities of aldolases in bacterial extracts differ approximately sixfold between the two expression plasmids in E. coli JM83. Aldolase A can compose up to 40% of the total protein in E. coli JM83 when expressed in pPB1, from which more than 100 mg of purified enzyme can be obtained per liter culture.
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PMID:Construction of a high-copy "ATG vector" for expression in Escherichia coli. 142 27

Intracellular and serum activities of aldolase (ALS) were biochemically determined in lymphocyte subpopulations from normal subjects and patients with B-chronic lymphocytic leukemia (B-CLL). Aldolase activity was significantly lower in T cells of CLL than in normal T cells (2.9 +/- 1.5 vs. 4.7 +/- 2.1 Sigma Units (SU)/6 x 10(6) cells, p < 0.05). The aldolase activity also was significantly (p < 0.001) lower (3.1 +/- 1.9 SU/6 x 10(6) cells) in CLL B lymphocytes than in normal B lymphocytes (18.1 +/- 6.5 SU/6 x 10(6) cells). Moreover, the serum levels of ALS in all patients with B-CLL were higher than that in normal subjects (8.1 +/- 5.8 vs. 2.2 +/- 0.8 SU/ml, p < 0.02). Our findings demonstrate that T lymphocytes from patients with B-CLL display enzyme activity different from that of normal T cells. This may reflect the abnormal maturity of the residual T cell population in B-CLL.
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PMID:Intracellular and serum levels of aldolase activity in B chronic lymphocytic leukemia. 147 33

Distribution of several glycolytic enzymes in the lenses of different vertebrate species and their organization in the calf lenses were studied. Though no general pattern of enzyme activities in different species is discernible, high activities of TPI followed, in decreasing order, by GAPDH, enolase, PK, LDH and aldolase appear to be more common. Our observation on the unusually high activities of aldolase in the pig, enolase in the sheep and LDH in the duck lens are interesting in view of the already known dual function of LDH as an enzyme and a structural protein (epsilon-crystallin) in duck. Controlled treatment with detergents Brij-58 and Triton X-100 caused distinctly differential purturbations in the lens cells. In spite of fiber membrane disruption and partial actin dissolution by Brij-58, no significant increase in the release of glycolytic enzymes compared to control was observed. This suggests that none of the enzymes existed as a completely soluble and freely diffusible fraction. But treatment with a strong detergent (Triton X-100) caused the release of higher amounts of enzymes suggesting either a direct or indirect interaction with the cytomatrix components. Aldolase appears to be maximally bound in the cytosol followed by TPI, GAPDH, LDH and PK in decreasing order. Although thin lens slices were incubated with the detergents for a total period of 40 min and the loss of fiber architecture and organization confirmed by light microscopy, in the Triton X-100 treated tissues less than 25% of the total activity of any enzyme except TPI appeared in the bathing medium.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Investigation of lens glycolytic enzymes: species distribution and interaction with supramolecular order. 155 53

Aldolase and triose phosphate isomerase both display strict specificity towards the enantiomers of [1-3H]glycerone 3-phosphate. The enantiomer generated from D-[1-3H]glyceraldehyde 3-phosphate produces 3HOH in the aldolase reaction, whilst the other enantiomer generated from D-[3-3H]fructose 1,6-bisphosphate is solely detritiated in the reaction catalyzed by triose phosphate isomerase. Advantage was taken of such a specificity to assess, in human erythrocytes exposed to either D-[3-3H]glucose or D-[3,4-3H]glucose, the extent of D-glyceraldehyde 3-phosphate sequential conversion to glycerone 3-phosphate and D-fructose 1,6-bisphosphate, relative to net glycolytic flux. At 37 degrees C and in the presence of 5.6 mM D-glucose, only 55% of the metabolites of D-[4-3H]glucose underwent detritiation in the reactions catalyzed by triose phosphate isomerase and aldolase. Such a percentage was further decreased at low temperature (8 degrees C) or lower concentrations of D-glucose (0.2 and 1.0 mM). However, when the erythrocytes were exposed to menadione, the increase in 3HOH production from either D-[3-3H]glucose or D-[3,4-3H]glucose indicated that the majority of the 3H atoms initially located on the C4 of D-glucose were recovered as 3HOH upon circulation through the pentose phosphate pathway. These findings suggest that, under physiological conditions, a large fraction of D-glyceraldehyde 3-phosphate generated from exogenous D-glucose may undergo enzyme-to-enzyme channelling in the glycolytic pathway.
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PMID:Interconversion of D-fructose 1,6-bisphosphate and triose phosphates in human erythrocytes. 159 48


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