["Enzymology" commission. Current enzymology in clinical chemistry and recommendations for the measurement of catalytic activities in the serum at 30 degrees C].
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Alkaline Phosphatase↗
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Staphylococcal nuclease reviewed: a prototypic study in contemporary enzymology. III. Correlation of the three-dimensional structure with the mechanisms of enzymatic action.
This is the third in a series of four articles in which the chemical, enzymological and crystallographic work on Ribonucleate (deoxribonucleate)-3'-nucleotidohydrolase, EC 3.1.4.4 (staphylococcal nuclease, micrococcal nuclease) will be reviewed and correlated. This article describes the structure of the nuclease and of a nuclease-inhibitor complex as determined by x-ray crystallography. The crystal structures are correlated with some of the known chemical and enzymological properties of the enzyme, and the three areas combined to propose a mechanism of action.
Amino Acid Sequence↗
Staphylococcal nuclease reviewed: a prototypic study in contemporary enzymology. II. Solution studies of the nucleotide binding site and the effects of nucleotide binding.
This is the second of a series of four articles in which the chemical, enzymological and crystallographic work on Ribonucleate (deoxyribonucleate)-3'-nucleotidohydrolase, EC 3.1.4.4. (staphylococcal nuclease, micrococcal nuclease) will be reviewed and correlated. This article discusses studies in solution delineating the extent of the binding site of the enzyme and identifying some of the particular amino acid residues that form this site. In addition, the effects of the very potent inhibitory combination of thymidine-3',5'-diphosphate and Ca2+ on the conformation of the enzyme and its physical, chemical and enzymological properties will be reviewed.
Binding Sites↗
[Lactate dehydrogenase. An example of the development of modern enzymology].
Lactate dehydrogenase is the prototype of an oligomeric, intracellular enzyme. Its primary, secondary, tertiary, and quaternary structures are now well known. This fact, especially with regard to the occurrence of isoenzymes, has effected a great progress in the understanding of the structure-function relationship of enzymes. The historical development of modern enzymology is described, together with discussions of the various methods and problems of enzymology.
Animals↗
The scientific foundations of clinical enzymology.
Clinical enzymology is the study of the activity and properties of enzymes in specimens (usually of blood) taken from patients, as an aid to the diagnosis and understanding of disease. Research in many areas of enzymology is undertaken to strengthen the foundations on which the clinical interpretation of such enzyme measurements rests. Some aspects of this research are briefly described.
Alkaline Phosphatase↗
Staphylococcal nuclease reviewed: a prototypic study in contemporary enzymology. I. Isolation; physical and enzymatic properties.
This is the first of a series of four articles in which the chemical, enzymological, and crystallographic work on Ribonucleate (deoxyribonucleate)-3'-nucleotidohydrolase, EC 3.1.4.7, (Staphylococcal nuclease, Micrococcal nuclease) will be reviewed and correlated. This article discusses the purification of the enzyme and its general physical and enzymological properties. Subsequent articles will deal with specific studies of the nucleotide binding site, crystallographic studies of a nuclease-inhibitor complex, use of the nuclease as a model for protein folding and possible mechanisms for the action of the enzyme.
Amino Acid Sequence↗
Clinical enzymology in cancer.
It is fair to say that so far, and with few exceptions, the application of enzymology to clinical oncology has been disappointing. This is certainly true with regard to cancer screening and diagnosis. It is unlikely that any single enzyme or isoenzyme will emerge as a sufficiently sensitive or specific indicator of cancer, and it would seem more profitable to focus on multivariate or pattern analysis of several enzymes and other measurable body fluid constituents. Another suggested approach would be to establish the normal enzyme levels for individuals and then follow them for changes which might signal the development of a neoplasm. Finally, Weber's concept of key enzymes as the phenotypic markers of neoplasia and targets of chemotherapy would appear to open a new avenue for enzymology in clinical oncology.
Humans↗
[Biometry, hematology, plasma biochemistry and plasma and tissues enzymology of the red partridge (Alectoris rufa) (author's transl].
The following parameters have been estimated in 15 red partridges (young adults of both sexes): 1. Biometry: relative weight of 10 organs (liver, kidneys, heart, brain, spleen, lungs, small gut, coecum, stomach, gizzard). 2. Hematology (mean +/- S.D.): Erythrocytes, 3.4 X 10(6) +/- 0.3 X 10(6) cells/mm3; packed cell volume 0.46 +/- 0.17; haemoglobin 103 +/- 27 g/l; mean red blood cell volume, 135.6 +/- 10.4 micrometer3; haemoglobin per red blood cell, 32.2 +/- 5,2 pg; haemoglobin concentration in red blood cells, 24.0 +/- 2.9 %; leukocytes, 36.9 X 10(3) +/- 7.8 X 10(3) cells/mm3; heterophilic, 32.3 +/- 8.3 %; basophilic, 5.3 +/- 1.5 %; eosinophilic, 1.4 +/- 1.5 %; lymphocytes, 56.1 +/- 7.3 %; monocytes, 4.6 +/- 1.4 %. 3. Blood biochemistry: Na +, 155 +/- 6 mEq/l; K +, 6.5 +/- 1.2 MEq/l; Cl--, 107 +/- 4 mEq/l; Pi, 53.3 +/- 14.4 mg/l; urea, 0.19 +/- 0.05 g/l; uric acid, 33.2 +/- mg/l; creatinin, 14.7 +/- 0.9 mg/l; glucose, 2.77 +/- 0.35 g/l; cholesterol, 1.38 +/- 0.36 g/l; total proteins, 44.1 +/- 5.9 g/l; albumin, 50.0 +/- 8.7 %; alpha globulins, 3.9 +/- 1.5 %; beta globulins, 7.5 +/- 2.2 %; gamma1 globulins, 31.5 +/- 5.6 %; gamma2 globulins 8.0 +/- 3.5 %. 4. Serum enzymology: Alkaline phosphatase, 8177 +/- 5078 u/l; SGOT, 356 +/- 138 u/l; SGTP 28.3 +/- 12.5 m/l; LDH, 955 +/- 570 m/l; GLD 12.6 +/- 12.4 u/l; CPD, 136 +/- 77 u/l; choline esterase, 2181 +/- 506 u/l. 5. Tissue enzymology: the 7 preceding enzymes have been estimated in 10 tissues listed in 1.
Alkaline Phosphatase↗
Staphylococcal nuclease reviewed: a prototypic study in contemporary enzymology. IV. The nuclease as a model for protein folding.
This is the last in a series of four articles in which the chemical, enzymological and crystallographic work on Ribonucleate (deoxyribonucleate)-3'-nucleotidohydrolase, EC 3.1.4.4 (staphylococcal nuclease, micrococcal nuclease) will be reviewed and correlated. This article discusses the use of the nuclease as a model system for the study of the mechanisms and energetics of the folding-unfolding reaction in proteins and for the study of the interrelationships between amino acid sequence and three-dimensional structure.
Epitopes↗
Alkaline lysis of mammalian cells for sedimentation analysis of nuclear DNA. Conformation of released DNA as monitored by physical, electron microscopic and enzymological techniques.
The degree of single strandedness of the DNA released from rat liver nuclei by various alkaline lysing solutions (including some with sodium dodecyl sulfate) was determined both before and after sedimentation in alkaline sucrose gradients employing electron microscopy, melting profiles, circular dichroism measurements, and digestibility by S1 nuclease. Regardless of the technique employed, the results obtained following alkaline sucrose gradient centrifugation of the DNA are consistent. The DNA was completely single stranded as judged by electron microscopy, circular dichroism spectra, and digestibility by S1 nuclease, an enzyme that specifically hydrolyzes single-stranded DNA. This was not true if the DNA was analyzed following alkaline lysis of the nuclei but before centrifugation. Under conditions which gave a complete transition to the single-stranded state, as judged by melting profiles and circular dichroism spectra, only 10-15% of the DNA was hydrolyzed by S1 nuclease. An increase in the susceptibility of the released DNA to S1 nuclease was observed with increases in the pH of the lysing solution. In order to release DNA which was single stranded as judged by both physical and enzymological techniques, the rat liver nuclei were lysed for 30 min with a 0.3 M NaOH lysing solution containing 0.5% dodecyl sulfate, 0.3 M NaCl and 0.03 M EDTA.
Animals↗
A patient with purine nucleoside phosphorylase deficiency: enzymological and metabolic aspects.
1. Enzymological and metabolic data in a patient with nucleoside phosphorylase (NP) deficiency are described. 2. Incubation of intact NP-deficient red cells with [14C]adenosine showed a rapid uptake and conversion to inosine. Almost no radioactivity was incorporated in the adenosine nucleotides and no hypoxanthine labeling could be detected. 3. Incubation with [14C]inosine resulted in a rapid conversion to IMP in the normal intact red cells but in an accumulation of inosine in the medium with the erythrocytes of the patient, proving again that a NP deficiency is present. 4. The high PRPP level found may result from impaired consumption due to lack of substrates for the salvage enzyme HGPRT. 5. Incubation with [14C]hypoxanthine and [14C]adenine showed that normal HGPRT and APRT activities were present in the NP-deficient red cells. 6. In serum and urine of the patient the levels of inosine and guanosine were considerably increased, while the serum and urinary levels of uric acid were very low. In the two deceased sisters NP deficiency was also strongly suggested by analyses of the serum purines, of stored deep frozen samples.
Adenine↗
Metachromatic leukodystrophy and age: a comparative study of clinical, enzymological and ultrastructural findings.
The clinical findings of three cases of metachromatic leukodystrophy, one of the late infantile, one of the juvenile and one of the adult variant are described and compared with those mentioned in relevant publications. Comparison of our findings lead us to conclude that a difference exists between the late infantile case on the one hand and the juvenile and the adult case on the other hand. This conclusion concurs with the results obtained by the enzymological study of the enzyme arylsulfatase A derived from the three cases. As to the characteristics of the enzyme arylsulfatase A, a difference was found to exist between the enzyme of the late infantile case on the one hand and that of the juvenile and the adult case on the other hand. The results of the electronmicroscopic investigation of peripheral nerve biopsy specimens of the three cases are briefly summarized. It is postulated that the ultrastructural findings do not justify any such distinction.
Adolescent↗
Evolutionary implications of different types of microbial enzymology for L-tyrosine biosynthesis.
Several patterns of enzymology for L-tyrosine biosynthesis exist in modern microorganisms, each differing in the apparent degree of regulatory efficiency. The extent of pathway evolution in a particular organism may reflect the relative selective pressure for regulation encountered in different ecological niches.
Bacillus subtilis↗
Biophysical and enzymological studies upon the interaction of trans-cinnamic acid with higher plant microsomal cytochromes P-450.
The interaction of trans-cinnamic acid with the cytochrome P-450 of microsomes derived from washed potato slices has been studied. The washing process increased the specific content of microsomal electron transport components and hence provided a useful material in which to study the interaction. Evidence is presented that the trans-cinnamic acid interacts with the cytochrome P-450, and that this interaction is analogous to "type 1" interactions of other cytochrome P-450 systems. This evidence includes the formation of a "type 1" substrate binding spectrum, an increased rate of reduction of cytochrome P-450 by NADPH in the presence of trans-cinnamic acid, an increased oxygen uptake and NADPH oxidation when trans-cinnamic acid is added to the microsomes in the presence of NADPH, and a close correlation between biophysical parameters of electron transport in the cytochrome P-450 system and enzymological parameters of the trans-cinnamic acid 4-hydroxulation reaction. The investigation has been extended to cytochrome P-450 systems of other tissues and it has been found that the trans-cinnamic acid 4-hydroxylation reaction cannot account for the presence of most of th cytochrome P-450 in several tissues. This suggests that other functions of higher plant cytochrome P-450 chains exist, and that the substrate specificityof the hemoprotein may vary in different plant tissues.
Antimycin A↗
Enzymology of ubiquinone-utilizing electron transfer complexes in nonionic detergent.
The enzymology of isolated succinate: ubiquinone reductase and ubiquinone: cytochrome c reductase in nonionic detergents (alkyl polyoxyethylene derivatives) was studied. In the membrane the two multiprotein complexes and their hydrophobic substrates ubiquinone and dihydroubiquinone, are embedded in a common lipid bilayer. In detergent solutions the complexes are each inserted into micelles. Detergent micelles also serve as a solvent for the complexes hydrophobic substrates. As a consequence the isolated complexes are in a discontinuous phase with respect to their hydrophobic substrates and with respect to each other. Three types of assays were used. Firstly, single enzyme assays in which the hydrophobic substrates had to transfer from free micelles to the complex-bound micelles in order for enzyme reactions to occur. Secondly, assays in which the enzymic reactions were coupled to auxiliary nonenzymic reactions which rapidly converted the hydrophobic products back into substrates within the complex-bound micelle. Dichloroindophenol was used for the oxidation of dihydroubiquinone and dihydroduroquinone for the reduction of ubiquinone. Thirdly, assays in which the succinate: ubiquinone reductase reaction was coupled with the ubiquinone: cytochrome c reductase reaction. With the first type of assay, the kinetics of the substrate transfer reaction was dependent upon the type of detergent. In detergents with small polyoxyethylene head groups the transfer reactions were rate-limiting, and in detergents with large polyoxyethylene head groups the transfer reactions were fast and the enzymic reactions were rate-limiting...
Animals↗
Chloramphenicol: an enzymological microassay.
A new assay for chloramphenicol in biological fluids has been developed that offers sensitivity, specificity, precision, accuracy, economy, and ease of performance. The assay is based on the enzymological acetylation of chloramphenicol catalyzed by an R factor-mediated enzyme. [(14)C]acetyl coenzyme A serves as the donor of the labeled acetyl group, and the product, [(14)C]acetoxychloramphenicol, is separated from the labeled precursor by utilizing its preferential extraction into benzene. The product is then quantified by liquid scintillation counting. This assay measures chloramphenicol concentrations in both plasma and other biological specimens and in the presence of other antibiotics, hemolysis, or jaundice. Its rapidity and ease of performance are useful for clinical laboratories, and its sensitivity allows determinations on 10 mul of plasma.
Acetylation↗
Enzymology of butyrate formation by Butyrivibrio fibrisolvens.
Butyrivibrio fibrisolvens is a major butyrate-forming species in the bovine and ovine rumen. The enzymology of butyrate formation from pyruvate was investigated in cell-free extracts of B. fibrisolvens D1. Pyruvate owas oxidized to acetylcoenzyme A (CoA) in the presence of CoA.SH and benzyl viologen or flavin nucleotides. The bacterium uses thiolase, beta-hydroxybutyryl-CoA dehydrogenase, crotonase, and crotonyl-CoA reductase to form butyryl-CoA from acetyl-CoA. Reduction of acetoacetyl-CoA to beta-hydroxybutyryl-CoA was faster with NADH than with NADPH. Crotonyl-CoA was reduced to butyryl-CoA by NADH, but not by NADPH, only in the presence of flavin nucleotides. Reduction of flavin nucleotides by NADH was much slower than the flavin-dependent reduction of crotonyl-CoA. This indicates that flavoproteins rather than free flavin participated in the reduction of crotonyl-CoA. Butyryl-CoA was converted to butyrate by phosphate butyryl transferase and butyrate kinase.
3-Hydroxyacyl CoA Dehydrogenases↗
Clinical aspects of gut enzymology.
Enzymological alterations in functional disturbances and in diseases of the intestine are reviewed. Examples are given for diagnostic significance (e.g. in Hirschsprung's and Crohn's diseases), for pathogenetic considerations (e.g. in hypolactasia and in celiac disease), and for secondary involvement of the liver (e.g. in intestinal tumors and after bypass surgery) and are discussed in more detail.
Acetylcholinesterase↗