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PubMed1991

Diagnostic and prognostic significance of serum cholinesterase and lactate dehydrogenase in breast cancer.

Serum cholinesterase (ChE) and Lactate dehydrogenase (LDH) activities were estimated in 40 cases of carcinoma breast, 25 cases of benign tumours and compared with healthy controls (30 cases). Significant difference in enzyme activities were obtained between benign and malignant neoplasms of the breast when compared with each other as well as when compared with healthy controls. Also, there were significant enzyme changes between non-metastatic cases and those with metastasis and when Stage I and Stage II cancers were compared with those in Stage III and Stage IV. No difference in enzyme levels were recorded between pre and post-operative cases and in different types of breast cancers. While ChE was depressed in 80 per cent cases of malignancy breast, serum LDH was raised in 73.3 per cent cases.

Breast Diseases↗

PubMed1989

Soybean L-(+)-lactate dehydrogenases: purification, characterization, and resolution of subunit structure.

Lactate dehydrogenase (LDH) (EC 1.1.1.27) from soybean (Glycine max) was purified 2360-fold to homogeneity using ion-exchange, hydroxyapatite, affinity, and hydrophobic chromatographies. The molecular weight of the holoenzyme is 150,000 +/- 5000. Two-dimensional (isoelectrofocusing-sodium dodecyl sulfate) gel electrophoresis reveals two polypeptides subunits of 5.9 and 6.5 pI and of 36,000 +/- 1000 and 37,000 +/- 1000 Mr, respectively. Nondissociating electrophoresis and isoelectric focusing of LDH resolved five tetrameric isoenzymes with pI's between 6.0 and 6.5. The data suggest that these LDH isoenzymes are derived from random association of the products of two different, but most probably related, genes. Kinetic measurements revealed substrate inhibition at high concentrations of lactic acid and biphasic kinetics with NAD.

Electrophoresis, Gel, Two-Dimensional↗

PubMed1991

[Characteristics of microsome-bound lactate dehydrogenase from skate white muscles].

Microsomes possessing the lactate dehydrogenase (LDH) activity were isolated from white driving muscles of the skate (Raja clavata) using differential centrifugation. It was shown that the increase of the ionic strength after addition of 0.6 M KCl and alkalinization of the medium result in the solubilization of the LDH activity - by 50% and 80%, respectively. The Km values for pyruvate and NADH are 171 microM and 7.5 mM, respectively. Membrane-bound LDH, is not inhibited by pyruvate excess (up to 20 mM); the rate of the enzyme inactivation by trypsin is 3 times as low as that of the solubilized enzyme. The existence of two-membrane-bound LDH pools is postulated. The enzyme from the first pool is bound to the membrane by electrostatic whereas the second pool LDH - by hydrophobic forces.

Animals↗

PubMed1976

Effects of subunit interactions on the activity of lactate dehydrogenase studied in immobilized enzyme systems.

Rabbit muscle lactate dehydrogenase (LDH) was coupled to Sepharose in such a way that each molecule is expected to be attached via only one subunit. Dissociation of the bound active enzyme by several methods all yielded immobilized subunit derivatives which were inactive. These derivatives were capable of regenerating activity by interacting specifically with subunits in solution formed transiently during renaturation. This ability to peck up soluble subunits is lost fairly rapidly upon storage of the immobilized subunits. Similarly, LDH subunits attached to Sepharose via disulfide bonds were found to be inactive. When these subunits were detached from the matrix by mild reduction with mercaptoethanol, activity was regenerated. The kinetics of this reactivation process suggests that reassociation is required for appearance of activity. All these results can be interpreted as showing that subunit interactions are essential for LDH activity.

Animals↗

PubMed1979

Structure of the flavin adduct formed in the suicide reaction of alpha-hydroxybutynoate with D-lactate dehydrogenase.

The Zn-dependent flavoenzyme D-lactate dehydrogenase from Megasphaera elsdenii is irreversibly inactivated by the D form of the suicide substrate 2-hydroxy-3-butynoic acid. The process of inactivation involves formation of a new pink chromophore, which can be released in intact form from the protein and which was purified to homogeneity by affinity chromatography. Inactivation involves covalent addition of the suicide substrate to the flavin coenzyme. The optical spectra indicate an elongation of the flavin chromophore, and the chemical reactivity suggests a derivative of reduced flavin. The structure of this adduct was deduced from Fourier transform NMR, from the chemical properties, and from comparison with appropriate models, which were synthesized chemically. This structure involves the covalent linkage of the acetylenic inhibitor to positions N(5) and C(6) of the flavin coenzyme via carbon atoms 2 and 4 of the inhibitor to form an additional fused aromatic ring. The pink adduct can be reconverted to an isoalloxazine chromophore by reduction with borohydride and subsequent reoxidation with oxygen. This new isoalloxazine has the spectral properties of an isoflavin, and it is proposed to carry the moiety of the inactivator molecule as substituent at position C(6). The structure of the pink chromophore representing a cyclic adduct to the flavin positions N(5) and C(6) is compared to that of the adduct obtained from L-lactate oxidase from Mycobacterium smegmatis and the L form of the same inhibitor [C(4a)--N(5) cyclic adduct; Schonbrunn, A., Abeles, R. H., Walsh, C. T., Ghisla, S., Ogata, H., and Massey, V. (1976) Biochemistry 15, 1978]. This comparison allows deductions about the relative orientation of substrate, coenzyme, and active center functional groups in the two enzymes.

Alkynes↗

PubMed1966

Cytochemical localization of lactate dehydrogenase in muscular dystrophy of the mouse.

By use of phenazine methosulfate and the "ncubation mixture film method," lactate dehydrogenase activity has been demonstrated in the dystrophic muscle fibers of strain 129 mice. The results indicate that for demonstration of lactate dehydrogenase activity in dystrophic muscle fibers phenazine methosulfate is necessary. This finding is typical for the "white" muscle fibers in the normal muscle and suggests that the dystrophy affects primarily the "white" muscle fibers.

Animals↗

PubMed1989

Species-specific responses of muscle lactate dehydrogenase isozymes to increased contractile activity.

Analyses of lactate dehydrogenase (LDH) isozymes were performed in normal and chronically stimulated (10 Hz, 10 h/d) tibialis anterior (TA) muscles of the mouse, rat, guinea pig, and rabbit. The electrophoretic mobilities of the individual LDH isozymes of normal muscles revealed species-specific patterns. Stimulation up to 28 days evoked increases in the percentage of the H-subunit of LDH. The absolute increase was highest in the rabbit, intermediate in the guinea pig and rat, and lowest in the mouse. The extent of the M- to H-subunit exchange, thus, appeared to be inversely correlated with the basal aerobic-oxidative capacities of the investigated muscles. In addition, a relationship between the expression of the H-subunit of LDH and the increase in aerobic-oxidative capacity became evident from these stimulation-induced processes of metabolic adaptation.

Animals↗

PubMed1985

Myasthenia gravis: long-term prognostic value of thymus lactate dehydrogenase isoenzyme pattern of hyperplastic thymus and thymoma.

Lactate dehydrogenase (LDH) isoenzyme pattern and the percent of H-subunit content were determined in the thymus of 62 patients (55 with hyperplasia, 7 with tumours) after thymectomy. An increase in LDH1 relative activity indicates that in the thymus of patients with myasthenia gravis the ratio of mature differentiated thymocytes was higher than in the thymus of control subjects. LDH isoenzyme profiles of thymus tumours were similar to those described in other neoplasms, except that thymomas with apparent predominance of epithelial cells and with minimal lymphocytic reaction exhibited a marked elevation only in LDH2 relative activity, presumably associated with the specific (secretory) function of epithelial cells. The elevation of H-subunit content, a parameter characteristic of both thymic components (lymphoid and epithelial), correlated closely with a poor clinical condition in patients several years after surgery.

Adolescent↗

PubMed1984

Estimation of the gene frequency of lactate dehydrogenase subunit deficiencies.

To detect the frequency of lactate dehydrogenase (LDH) subunit deficiency, screening for LDH subunit deficiency was performed on 3,776 blood samples from healthy individuals in Shizuoka Prefecture by means of electrophoresis. The frequency of heterozygote with LDH-A subunit deficiency was found to be 0.185%, and with LDH-B subunit deficiency, 0.159%. The frequencies of both subunit deficiencies were not significantly different. Gene frequencies of LDH subunit deficiencies were calculated by the simple counting procedure, and the results are as follows: gene frequency of LDH-A subunit deficiency was 11.9 X 10(-4), and that of LDH-B subunit deficiency, 7.9 X 10(-4). In addition, the second case in the world of a homozygous individual with LDH-A subunit deficiency was detected by this screening. This case with regard to the characteristics of LDH-A subunit deficiency are summarized herein.

Erythrocytes↗

PubMed1978

Flow kinetics of lactate dehydrogenase chemically attached to nylon tubing.

Rabbit muscle lactate dehydrogenase (EC 1.1.1.27) was attached covalently to the inner surface of nylon tubing; a modified technique, involving benzidine and glutaraldehyde, was used, and the resulting immobilized enzyme showed no loss of activity over a period of several months. An experimental study was made of the flow kinetics for the reaction between pyruvate and reduced nicotinamide adenine dinucleotide in two limiting cases, one substrate in excess and the concentration of the other one varied. A range of flow rates and temperatures was covered. The results were analyzed in various ways on the basis of the Kobayashi--Laidler treatment of flow systems. It was concluded that the kinetics are largely diffusion-controlled, especially at the lower substrate concentrations and flow rates. The values of the apparent Michaelis constants vary with flow rate vf, being linear in vf-1/3, and the values extrapolated to infinite flow rate (vf-1/3 = 0) approach the values for the enzyme in free solution. Analysis of the rates led to activation energies for the diffusion of the two substrates.

Enzymes, Immobilized↗

PubMed1977

Sources of normal variation of plasma lactate dehydrogenase in range cattle.

1. Plasma levels of lactate dehydrogenase (LD) were estimated in Hereford cattle of 1 month to 12 yr of age kept under range conditions. 2. Plasma levels of LD were estimated in a group of confined cows and their calves fed a constant diet and kept in individual pens in the same geographic area as the range Herefords. 3. Large seasonal changes in mean plasma LD were observed in the range cattle but not in the confined, constant diet group. The seasonal changes corresponded with the appearance of new growth on the range. 4. Changes in plasma LD were observed at weaning time in the range cattle but not in the confined group. 5. Sex had no effect upon plasma LD levels in the juvenile animals of either group. No comparison of adult animals could be made. 6. Mean plasma LD levels did not change with age but the seasonal effect decreased in magnitude as the animals matured. 7. An increase in plasma LD was observed around the first ovulation in the confined animals. 8. A decrease in plasma LD was observed during parturition in the confined group.

Animals↗

PubMed1990

Cloning of a lactate dehydrogenase gene from Clostridium acetobutylicum B643 and expression in Escherichia coli.

A lactate dehydrogenase (LDH) gene of Clostridium acetobutylicum B643 was cloned on two recombinant plasmids, pPC37 and pPC58, that were selected by complementation of Escherichia coli PRC436 (acd), a fermentation-defective mutant that does not grow anaerobically on glucose. E. coli PRC436(pPC37) and PRC436(pPC58) grew anaerobically and fermented glucose to mostly lactate. When pPC37 and pPC58 were transformed into E. coli FMJ39 (ldh pfl), an LDH-deficient strain, the resulting strains grew anaerobically on glucose and produced lactate. Crude extracts of E. coli FMJ39(pPC37) and FMJ39(pP58) contained high LDH activity only when assayed for pyruvate reduction to lactate, and the LDH activity was activated 15- to 30-fold by the addition of fructose 1,6-diphosphate (FDP). E. coli FMJ39 had no detectable LDH activity, and E. coli LDH from a wild-type strain was not activated by FDP. Maxicell analysis showed that both plasmids pPC37 and pPC58 expressed a protein with an apparent Mr of 38,000 in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Restriction endonuclease mapping of pPC37 and pPC58 and DNA hybridization studies indicated that a 2.1-kb region of these two clones of C. acetobutylicum DNA encodes the FDP-activated LDH.

Cloning, Molecular↗

PubMed1987

Serum creatine kinase and lactate dehydrogenase during cardiac irradiation.

Thirty patients irradiated to a major part of the heart had serial determinations of serum total creatine kinase (S-CK), creatine kinase subunit B (S-CK-B), total lactate dehydrogenase (S-LD) and lactate dehydrogenase isoenzyme 1 (S-LD-1) activity at the beginning, at the end and 1-4 months after radiotherapy. One patient had an elevated total S-CK activity three months after radiotherapy, but none of the patients had an elevated S-CK-B activity during follow-up. Three patients had elevated serum LD before irradiation, two patients during and two patients after radiotherapy, but only one patient had an elevated S-LD-1 activity, which decreased during irradiation. We conclude that the heart muscle is not injured by cardiac irradiation to such an extent that CK, CK-B, LD and LD-1 activities rise in serum, if moderate doses (39-62 Gy, NSD 1,137-1,775 rets) are delivered to the heart.

Adult↗

PubMed1968

Lactate dehydrogenase activity in certain strains of Staphylococcus aureus.

Lactate dehydrogenase (LDH) was studied in phage-propagating strains 29, 3A, 6, 81, and 42D of Staphylococcus aureus selected from the five groups in the International-Blair series. Cells were cultivated in Brain Heart Infusion (Difco) under nearly anaerobic conditions and were harvested near the end of the log phase. LDH activity was maximal at the end of the exponential growth period and was measured spectrophotometrically by reduction of p-nitro-blue tetrazolium, with phenazine methosulfate as a coupling agent. Crude enzyme extracts were prepared both by an acetone extraction technique and by sonic treatment. LDH activity for these enzyme preparations was determined by the colorimetric method mentioned and also by measuring the rate of nicotinamide adenine dinucleotide reduction at 340 mmu. The order of activity observed, by use of both assay methods, was 29 > 81 > 6 > 3A > 42D. LDH forms (possibly isoenzymes) for each of 15 strains, which represent the five phage-propagating groups of the International-Blair series, were separated by acrylamide gel electrophoresis. Five forms were distinguished and arbitrarily numbered on the basis of their rate of migration, no. 5 being the slowest component. No one strain had more than four, nor fewer than two, LDH forms. Form 3 appeared in 13 of the 15 strains and was followed in frequency by no. 2, 1, 4, and 5.

Culture Media↗

PubMed1989

Lactate dehydrogenase isoenzyme patterns in bovine liver tissue.

Liver lactate dehydrogenase (LDH) isoenzymes in normal and diseased cows were analyzed electrophoretically. This method (histoelectrophoresis) was improved for the direct analysis of tissue LDH isoenzymes. The mean values of LDH 1 through LDH 5 in the livers of normal cows were 31.7, 24.8, 27.3, 12.8, and 3.3%, respectively. In cases with hydropic degeneration of the liver, the patterns revealed increases of LDH 1 and LDH 2 as compared to normal cows. The patterns showed a decrease of LDH 1 and an increase of LDH 2 in fatty change of the liver. Congestion of the liver alone decreased LDH 1 and increased LDH 3, LDH 4 and LDH 5. Necrosis of the liver decreased LDH 1 and LDH 2, and increased LDH 3, LDH 4 and LDH 5. It was suggested that the functional hepatocellular damage due to anoxia might be a important factor of the change of liver LDH isoenzyme patterns. We have attempted to standardize the LDH isoenzyme patterns by using a computer under various conditions. In cases with hydropic lesions, the diagnostic sensitivity (DS) was 53% (28 of 53 cases) and the predictive value of positive tests (PVPT) was 100% (28 cases of 28 cases selected). In cases with congestive or necrotic lesions, DS was 41% (9 of 22 cases) and PVPT was 69% (9 cases of 13 cases selected).

Animals↗

PubMed1987

Mechanisms of compensation of hemolytic anemia in a lactate dehydrogenase mouse mutant.

Hemopoiesis was studied in homozygous lactate dehydrogenase (LDH) mutant mice not showing noticeable impairment in viability and fertility but afflicted with a severe hemolytic anemia. In order to investigate the mechanisms of erythropoietic compensation, the numbers of multipotent hemopoietic stem cells (CFU-S), myeloid (GM-CFC), and early and late erythroid progenitors (BFU-E and CFU-E) in femur and spleen were determined, and the total body content of each cell type was computed. While the total CFU-S and GM-CFC numbers showed only slight deviations from normal, the total BFU-E pool was 1.4 and the CFU-E pool 18 times enlarged. No difference in cell cycle status could be detected in these compartments by means of tritiated thymidine (3H-TdR) suicide in vitro. However, splenic erythroblasts of homozygous LDH mutants had a shorter DNA synthesis time and a higher labeling index compared to the wild type mice. It is concluded that the hemolysis is compensated at a lower level of red blood cell count primarily by an increase in the total number of late erythroid progenitors resulting from roughly four extra divisions, and secondarily by an increase in the flux through the recognizable erythroblast compartments, predominantly a space-saving mechanism.

Anemia, Hemolytic↗

PubMed1986

Cloning, expression and complete nucleotide sequence of the Bacillus stearothermophilus L-lactate dehydrogenase gene.

The structural gene for L-lactate dehydrogenase (LDH; EC 1.1.1.27) from Bacillus stearothermophilus NCA 1503 has been cloned in Escherichia coli and its complete nucleotide sequence determined. The predicted amino acid (aa) sequence of the LDH enzyme agrees with the previously determined aa sequence except to three positions: aa 125 and 126, Ser-Glu, are inverted whilst His at position 130 has been replaced by Ser in our sequence. The lct gene consists of an open reading frame (ORF) commencing from the ATG start codon of 951 bp followed by a TGA stop codon. Upstream from the start codon is a strong (delta G = -14.4 kcal) Shine-Dalgarno (SD) sequence, a feature typical of Gram-positive ribosome binding sites. Putative RNA polymerase recognition signals (-35 and -10 regions) have been identified upstream from the lct structural gene but there are no structures resembling Rho-independent transcription termination signals downstream from the TGA stop codon. Two further ORFs, preceded by SD sequences, are present downstream from the lct gene. Thus the lct gene may constitute the first gene of an operon. Subclones of the lct gene have been constructed in the expression plasmid pKK223-3 and the LDH enzyme produced in soluble form at levels of up to 36% of the E. coli soluble cell protein.

Amino Acid Sequence↗

PubMed1994

Analysis of the rat lactate dehydrogenase A subunit gene promoter/regulatory region.

The rat lactate dehydrogenase (LDH) A subunit gene promoter contains a putative AP-1 binding site at -295/-289 bp, two consensus Sp1 binding sites at -141/-136 bp and -103/-98 bp, and a single copy of a consensus cyclic AMP-responsive element (CRE) at -48 to -41 bp upstream of the transcription initiation site. Additionally, an as yet unidentified silencer element is located within the -1173/-830 bp 5'-flanking region. Transient transfection analyses of a -1173/+25 bp LDH A-chLoramphenicol acetyltransferase fusion gene has indicated a complete inability of the promoter fragment to direct basal or forskolin-induced transcription. Deletion of the -1173/-830 bp sequence restored basal and cyclic AMP (cAMP)-inducible activity. Point mutations in the Sp1 binding sites of a -830/+25 bp promoter fragment reduced basal but not the relative degree of cAMP-inducible activity. cAMP-regulated transcriptional activity was dependent upon an 8 bp CRE, -TGACGTCA-, located at the -48/-41 bp upstream region. Mutations in the CRE abolished cAMP-mediated induction and reduced basal activity by about 65%. The CRE binds a 47 kDa protein which has previously been identified as CRE binding protein (CREB)-327, an isoform of the activating transcription factor/CREB transcription factor gene family. Co-transfection of a vector that expresses the catalytic subunit of cAMP-dependent protein kinase stimulates LDH A subunit promoter activity suggesting that cAMP induces LDH A subunit gene expression through phosphorylative modification of CREB-327. This study emphasizes a fundamental role of several modules including Sp1 and CREB binding sites in regulating basal and cAMP-mediated transcriptional activity of the LDH A gene.

Animals↗