Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.1.1.1 (alcohol dehydrogenase)
 9,284 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The activities of class I and II alcohol dehydrogenase isoenzymes were examined in the sera of patients with non-alcoholic liver cirrhosis using a fluorometric method. The analysis of these results shows a statistically significant increase (2,5-times) in the activity of class I alcohol dehydrogenase, and no marked differences in the activity of class II in cirrhotic and control patients. The observed increase in total enzyme activity measured using a photometric method was not very high but confirmed the elevation of class I isoenzyme activity. Activities of both classes of alcohol dehydrogenase isoenzymes have a good correlation with aspartate aminotransferase. Class II isoenzyme activity additionally correlates with alkaline phosphatase. These results suggest that serum activity of class I alcohol dehydrogenase is a better indicator of liver cell destruction during non-alcoholic cirrhosis than total enzyme activity, and is comparable with the value of aspartate aminotransferase.
 ...
PMID:Human alcohol dehydrogenase isoenzyme activity in the sera of non-alcoholic liver cirrhotic patients. 893 2

In studies of pressure-induced subunit dissociation of protein aggregates, now widely used to evaluate the association free energy, entropy and enthalpy of very stable complexes, it is assumed that high pressure does not influence their structure/thermodynamic parameters and that some peculiarities of these equilibria, such as the decrease in subunit affinity at larger degrees of dissociation (alpha) and hysteresis in alpha/pressure diagrams are imputable to the slow conformational drift of isolated subunits. To test this premise, the conformation of dimeric alcohol dehydrogenase from horse liver and alkaline phosphatase from Escherichia coli was monitored as a function of pressure (up to 3 kbar) and temperature (0 to 50 degrees C) by means of the intrinsic Trp fluorescence and phosphorescence emission and binding of the 1-anilinonaphatalene-8-sulphonic acid (ANS) fluorophore. The results show a distinct influence of high pressure on the native dimers whose changes in conformation may, depending on whether or not these alterations are promptly reversed, be distinguished in elastic and inelastic changes. Elastic changes are ubiquitous and refer to pronounced modulations of the phosphorescence lifetime which is a monitor of the internal flexibility of the macromolecules. They attest to a tightening of the globular structure in the lower pressure range (below 1.5 kbar) as opposed to an increased fluidity in the higher range. The trend is similar between the two proteins and the tightening/loosening effect is fully consistent with the role that internal cavities and hydration of polypeptide is expected to play in determining the compressibility of these biopolymers. Inelastic perturbations reveal a more profound loosening of the globular fold and were observed only with alcohol dehydrogenase under conditions (low temperature (t < 10 degrees C) and high pressure (p > 2.5 kbar)) that favour protein hydration. They involve slow consecutive reactions that produce drastic reductions in phosphorescence lifetime, spectral red shifts, quenching of fluorescence and phosphorescence emission and modulation of ANS binding. Judging from the full protection afforded by glycerol as cosolvent, or the remarkable enhancement caused by modest concentrations of urea, the driving force of these perturbations appears to be pressure-induced hydration of the protein. Inelastic conformational changes are accompanied by a slow and often incomplete recovery of enzymatic activity. The characteristic times of these processes, their pressure dependence and the slow, thermally activated, reversibility are discussed in the light of hysteresis phenomena and changes of subunit affinity in dissociation equilibria.
 ...
PMID:Pressure effects on the structure of oligomeric proteins prior to subunit dissociation. 894 76

We examined the activity of class I and II of alcohol dehydrogenase isoenzymes in the sera of patients with viral hepatitis using fluorogenic substrates, 4-methoxy-1-naphthaldehyde for class I and 6-methoxy-2-naphthaldehyde for class II. It was found that serum activities of class I and II of alcohol dehydrogenase isoenzymes during five weeks of hospitalisation were higher than that of control. The greatest increase in activities was found at the onset of disease, and exceeded the mean control value about 30 times for class I and 4 times for class II. These were lower than the aminotransferase activities but higher than the activity of lactate dehydrogenase, alkaline phosphatase and gamma-glutamyltransferase. In the following periods of investigation the activity of alcohol dehydrogenase isoenzymes gradually decreased, but did not reach the values of the control groups in the last period of the study. Activity of class I and II of alcohol dehydrogenase isoenzymes showed a good correlation with alanine and aspartate aminotransferase and lactate dehydrogenase in the first weeks of the illness. These results clearly demonstrate that particularly the activity of class I of alcohol dehydrogenase isoenzymes measured by a fluorimetric method can be a useful marker of liver cell damage in the course of viral hepatitis.
 ...
PMID:Human serum alcohol dehydrogenase isoenzymes as a markers of liver injury during viral hepatitis. 902 May 38

Using new fluorogenic substrates, we measured the activity of class I and II alcohol dehydrogenase (ADH) isoenzymes in the sera of patients with obstructive jaundice. The activity of class I isoenzymes was elevated two-fold, whereas that of class II isoenzymes was unchanged. This increase of class I isoenzymes explains low increase of total serum ADH activity. ADH isoenzymes and total enzyme activities correlated better with aminotransferases, than with alkaline phosphatase and gamma-glutamyltransferase, but we can conclude that class I ADH isoenzymes measured with fluorogenic substrates are indicative of obstructive jaundice.
 ...
PMID:Activity of class I and II isoenzymes of alcohol dehydrogenase measured by a fluorometric method in the sera of patients with obstructive jaundice. 924 33

The treatment of Caco-2 cells, a human colon adenocarcinoma cell line that closely resembles normal human small intestinal epithelial cells, with acetaldehyde resulted in significantly decreased activities of brush border enzymes sucrase, maltase, lactase, and gamma-glutamyltransferase; alkaline phosphatase activity was not affected. In the case of sucrase and maltase, the activities were also decreased by a combination of acetaldehyde and ethanol, although ethanol alone markedly increased them. The possibility that intraintestinal acetaldehyde, formed by intestinal microbes, might play a role in some small intestinal enzyme deficiencies observed earlier in alcoholics should therefore be considered. The mechanism by which acetaldehyde alters these enzyme activities remains unclear. The observation that acetaldehyde also disturbed cell polarization, an initial step in the process of differentiation in Caco-2 cells, indicates that acetaldehyde might decrease these enzyme activities by interfering with cell differentiation. Because ethanol and acetaldehyde metabolizing enzymes have not been previously studied from Caco-2 cells, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) activities were also measured from these cells, and their ALDH isoenzyme pattern was characterized. Like many cancerous cell lines, Caco-2 cells were found to express no ADH. They, however, possessed ALDH activity that was comparable with normal colonic mucosal activity and also expressed the same ALDH classes (ALDHs 1 to 3) than normal human colonic mucosa.
 ...
PMID:Effects of acetaldehyde on brush border enzyme activities in human colon adenocarcinoma cell line Caco-2. 943 18

Results of kinetic studies on dissociative thermal inactivation of oligomeric enzymes are discussed. Dissociative thermal inactivation is the process in which the kinetically irreversible protein change is preceded by a reversible stage of oligomer dissociation. In experiments, this is demonstrated by the dependence of inactivation rate on total protein concentration. This paper gives the relations which allow the calculation from experimental data the following physicochemical constants which characterize the stability of oligomeric enzymes: the constant for the rate of irreversible change of monomeric protein, the equilibrium constant for dimer dissociation, and the rate constant for dimer dissociation. The problem of a "conformational lock", the contact between protein globules that admits a multistep destruction of active oligomer and explains the induction period occurring in kinetic thermal inactivation curves, is discussed. The X-ray structural analyses for several dimeric enzymes, i.e., alkaline phosphatase (EC 3.1.3.1) from E. coli, alcohol dehydrogenase (EC 1.1.1.1) from horse liver, and baker's yeast enolase (EC 4.2.1.11), explain why they lose catalytic activity during the dissociation of the protein into monomers and also provide a physically reasonable picture of the structure of their conformational lock. Also, these data support the kinetic scheme used to describe the dissociative inactivation of dimeric enzymes.
 ...
PMID:Dissociative thermal inactivation, stability, and activity of oligomeric enzymes. 952 27

The activities of classes I and II alcohol dehydrogenase isoenzymes were determined in the sera of patients with toxic hepatitis using class-specific fluorogenic substrates. The activities of total alcohol dehydrogenase and enzymes indicative of liver damage were also measured. We found a statistically significant increase of class I alcohol dehydrogenase isoenzymes. The increase in class I (two-fold) was similar to the increase of alkaline phosphatase. In a correlated study, we observed a good correlation of the activity of class II isoenzymes with alanine aminotransferase. The total alcohol dehydrogenase activity was enhanced and correlated with lactate dehydrogenase. These results demonstrated that the alcohol dehydrogenase and class I isoenzymes are indicatory enzymes of liver cell damage, and may be diagnostically useful in toxic hepatitis.
 ...
PMID:Serum activities of classes I and II alcohol dehydrogenases in toxic liver damage. 956 31

Recent findings on the biochemical and molecular features of the following thermozymes are presented, based on their biotechnological use: alpha-amylase and amylopullulanase, used in starch processing; glucose isomerase, used in sweetener production; alcohol dehydrogenase, used in chemical synthesis; and alkaline phosphatase, used in diagnostics. The corresponding genes and recombinant proteins have been characterized in terms of sequence similarities, specific activities, thermophilicity, and unfolding kinetics. Site-directed and nested deletion mutagenesis were used to understand structure-function relationships. All these thermozymes display higher stability and activity than their counterparts currently used in the biotechnology industry.
 ...
PMID:Thermozymes: biotechnology and structure-function relationships. 978 63

Parotid and mandibular saliva was obtained from red kangaroos by concurrent acetylcholine isoprenaline stimulation. Salivary proteins were separated by horizontal electrophoresis on either cellulose acetate or starch gels and assessed by specific staining techniques for 23 enzymes commonly found in mammalian tissues and body fluids. Parotid saliva was positive for acid phosphatase, alpha-amylase, carbonic anhydrase, glucose-6-phosphate dehydrogenase, sorbitol dehydrogenase and superoxide dismutase activities. Mandibular saliva was positive for alcohol dehydrogenase in addition to the above six enzymes. The kangaroo salivas lacked activity for alkaline phosphatase, beta-galactosidase and non-specific esterase which occur in saliva from some mammalian species.
 ...
PMID:Enzyme activity in parotid and mandibular saliva from red kangaroos, Macropus rufus. 978 23

Pressure is an effective modulator of protein structure and biological function. The influence of hydrostatic pressure (</=3 kbar, 10-50 degrees C) on conformational dynamics was assessed from the rate of migration of acrylamide through the protein interior. Migration rates in apoazurin, alcohol dehydrogenase and alkaline phosphatase were obtained from the phosphorescence quenching rate constant (kq) of the deeply buried Trp residues. The dominant effect of applied pressure is to slow the diffusion process, although at low temperature, high pressure may also accelerate it. For apoazurin, alcohol dehydrogenase and alkaline phosphatase the activation free volumes, DeltaV(obs), derived from the pressure-dependence of kq, ranges from +10, +16 and +20 ml mol(-1)at 50 degrees C to -20, +5 and 0 ml mol(-1)at 10 degrees C, respectively. Analysing DeltaV(obs) in terms of a positive contribution from cavity expansion and a negative one from peptide hydration, the results emphasise that whereas at warm temperature the formation of cavities plays a dominant role in the migration process, at low temperature the required flexibility may be conferred by internal protein hydration. The relatively small magnitude of both DeltaV(obs) and the activation enthalpy (DeltaH=10-20 kcal mol(-1)) indicates that acrylamide diffusion jumps inside these proteins appear to involve relatively small amplitude structural fluctuations not requiring major unfolding-like transitions. The implication of these findings for the thermodynamic stability of proteins under pressure is discussed.
 ...
PMID:Pressure/temperature effects on protein flexibilty from acrylamide quenching of protein phosphorescence. 1045 99


<< Previous 1 2 3 4 5 6 7 8 Next >>