Expression cloning of the nox, mdh and ldh genes from Thermus species encoding NADH oxidase, malate dehydrogenease and lactate dehydrogenase

1994 ◽  
Vol 40 (5) ◽  
pp. 676-681 ◽  
Author(s):  
Ho-Jin Park ◽  
Roland Kreutzer
Keyword(s):  
Lactate Dehydrogenase ◽  
Nadh Oxidase ◽  
Expression Cloning

scholarly journals Cellular localization of D-lactate dehydrogenase and NADH oxidase fromArchaeoglobus fulgidus

Archaea ◽  
2002 ◽  
Vol 1 (2) ◽  
pp. 95-104 ◽  
Author(s):  
Vishwajeeth Reddy Pagala ◽  
Joohye Park ◽  
David W. Reed ◽  
Patricia L. Hartzell
Keyword(s):  
Lactate Dehydrogenase ◽  
Cellular Localization ◽  
Nadh Oxidase ◽  
Optimal Growth ◽  
Binding Pocket ◽  
Integral Membrane Protein ◽  
Dissimilatory Sulfate Reduction ◽  
Gene Encoding ◽  
Thin Sections ◽  
Whole Cells

Members of the genusArchaeoglobusare hyperthermophilic sulfate reducers with an optimal growth temperature of 83 °C.Archaeoglobus fulgiduscan utilize simple compounds including D-lactate, L-lactate and pyruvate as the sole substrate for carbon and electrons for dissimilatory sulfate reduction. Previously we showed that this organism makes a D-lactate dehydrogenase (Dld) that requires FAD and Zn2+for activity. To determine the cellular location and topology of Dld and to identify proteins that interact with Dld, an antibody directed against Dld was prepared. Immunocytochemical studies using gold particle-coated secondary antibodies show that more than 85% of Dld is associated with the membrane. A truncated form of Dld was detected in immunoblots of whole cells treated with protease, showing that Dld is an integral membrane protein and that a significant portion of Dld, including part of the FAD-binding pocket, is outside the membrane facing the S-layer. The gene encoding Dld is part of an operon that includesnoxA2, which encodes one of several NADH oxidases inA. fulgidus. Previous studies have shown that NoxA2 remains bound to Dld during purification. Thin sections ofA. fulgidusprobed simultaneously with antibodies against Dld and NoxA2 show that both proteins co-localized to the same sites in the membrane. Although these data show a tight interaction between NoxA2 and Dld, the role of NoxA2 in electron transport reactions is unknown. Rather, NoxA2 may protect proteins involved in electron transfer by reducing O2to H2O2or H2O.

Inhibition of NADH oxidase and lactate dehydrogenase of mycoplasma gallisepticum by copper complexes of 2,2'-bipyridyl analogues

1987 ◽  
Vol 36 (19) ◽  
pp. 3237-3241 ◽  
Author(s):  
H.-Dieter Gaisser ◽  
John De Vries ◽  
Henk Van Der Goot ◽  
Henk Timmerman
Keyword(s):  
Lactate Dehydrogenase ◽  
Copper Complexes ◽  
Nadh Oxidase ◽  
Mycoplasma Gallisepticum

scholarly journals Loss of NADH Oxidase Activity in Streptococcus mutans Leads to Rex-Mediated Overcompensation in NAD+Regeneration by Lactate Dehydrogenase

2015 ◽  
Vol 197 (23) ◽  
pp. 3645-3657 ◽  
Author(s):  
J. L. Baker ◽  
A. M. Derr ◽  
R. C. Faustoferri ◽  
R. G. Quivey
Keyword(s):  
Oxidative Stress ◽  
Lactate Dehydrogenase ◽  
Stress Response ◽  
Streptococcus Mutans ◽  
Parent Strain ◽  
Nadh Oxidase ◽  
Oral Streptococci ◽  
Pathogenic Potential ◽  
Oral Pathogen ◽  
Content Type

ABSTRACTPrevious studies of the oral pathogenStreptococcus mutanshave determined that this Gram-positive facultative anaerobe mounts robust responses to both acid and oxidative stresses. The water-forming NADH oxidase (Nox; encoded bynox) is thought to be critical for the regeneration of NAD+, for use in glycolysis, and for the reduction of oxygen, thereby preventing the formation of damaging reactive oxygen species. In this study, the free NAD+/NADH ratio in anoxdeletion strain (Δnox) was discovered to be remarkably higher than that in the parent strain, UA159, when the strains were grown in continuous culture. This unanticipated result was explained by significantly elevated lactate dehydrogenase (Ldh; encoded byldh) activity andldhtranscription in the Δnoxstrain, which was mediated in part by the redox-sensing regulator Rex. cDNA microarray analysis ofS. mutanscultures exposed to simultaneous acid stress (growth at a low pH) and oxidative stress (generated through the deletion ofnoxor the addition of exogenous oxygen) revealed a stress response synergistically heightened over that with either stress alone. In the Δnoxstrain, this elevated stress response included increased glucose phosphoenolpyruvate phosphotransferase system (PTS) activity, which appeared to be due to elevatedmanLtranscription, mediated in part, like elevatedldhtranscription, by Rex. While the Δnoxstrain does possess a membrane composition different from that of the parent strain, it did not appear to have defects in either membrane permeability or ATPase activity. However, the altered transcriptome and metabolome of the Δnoxstrain were sufficient to impair its ability to compete with commensal peroxigenic oral streptococci during growth under aerobic conditions.IMPORTANCEStreptococcus mutansis an oral pathogen whose ability to outcompete commensal oral streptococci is strongly linked to the formation of dental caries. Previous work has demonstrated that theS. mutanswater-forming NADH oxidase is critical for both carbon metabolism and the prevention of oxidative stress. The results of this study show that upregulation of lactate dehydrogenase, mediated through the redox sensor Rex, overcompensates for the loss ofnox. Additionally,noxdeletion led to the upregulation of mannose and glucose transport, also mediated through Rex. Importantly, the loss ofnoxrenderedS. mutansdefective in its ability to compete directly with two species of commensal streptococci, suggesting a role fornoxin the pathogenic potential of this organism.

scholarly journals Competence Regulation by Oxygen Availability and by Nox Is Not Related to Specific Adjustment of Central Metabolism inStreptococcus pneumoniae

2001 ◽  
Vol 183 (9) ◽  
pp. 2957-2962 ◽  
Author(s):  
Sabine Chapuy-Regaud ◽  
Frédérique Duthoit ◽  
Laurence Malfroy-Mastrorillo ◽  
Pierre Gourdon ◽  
Nic D. Lindley ◽  
...  
Keyword(s):  
Lactate Dehydrogenase ◽  
Oxidase Activity ◽  
Nadh Oxidase ◽  
Lactate Production ◽  
Oxygen Availability ◽  
Glycolytic Flux ◽  
Mrna Levels ◽  
Central Metabolism ◽  
Loss Of Function ◽  
Nadh Oxidase Activity

ABSTRACT In Streptococcus pneumoniae oxygen availability is a major determinant for competence development in exponentially growing cultures. NADH oxidase activity is required for optimal competence in cultures grown aerobically. The implication of oxidative metabolism and more specifically of Nox on central metabolism has been examined. Glycolytic flux throughout exponential growth revealed homolactic fermentation with a lactate production/glucose utilization ratio close to 2, whatever the aerobiosis level of the culture. Loss-of-function mutations in nox, which encodes NADH oxidase, did not change this trait. Consistently, mRNA levels of glyceraldehyde-3-phosphate dehydrogenase, l-lactate dehydrogenase, pyruvate oxidase, and NADH oxidase remained comparable to wild-type levels, as did the specific activities of key enzymes which control central metabolism. Competence regulation by oxygen involving the NADH oxidase activity is not due to significant modification of carbon flux through glycolysis. Failure to obtain loss-of-function mutation in L-ldh, which encodes thel-lactate dehydrogenase, indicates its essential role in pneumococci whatever their growth status.

The osmotic lysis of spiroplasma cells and its use in enzyme studies

1994 ◽  
Vol 40 (9) ◽  
pp. 791-794 ◽  
Author(s):  
Jianchi Chen ◽  
C. J. Chang
Keyword(s):  
Lactate Dehydrogenase ◽  
Malate Dehydrogenase ◽  
Citrate Synthase ◽  
Nadh Oxidase ◽  
Tricarboxylic Acid Cycle ◽  
Spiroplasma Citri ◽  
Cell Lysates ◽  
Wash Buffer ◽  
Osmotic Lysis ◽  
Spiroplasma Melliferum

A simple and efficient osmotic lysis method was developed for enzyme studies in spiroplasmas. Log phase cells in R2 medium were harvested by centrifugation (19 600 × g for 30 min). Wash buffer supplemented with 0.23 M sucrose maintained the helicity of spiroplasma cells during washing. Osmotic lysis of spiroplasmas was achieved in H buffer that contained no sucrose. Sucrose at concentrations as low as 0.004 M dramatically increased the resistance of the spiroplasmas to osmotic lysis. NADH oxidase, lactate dehydrogenase, and malate dehydrogenase were detected in cell lysates of Spiroplasma floricola (23-6), Spiroplasma citri (R8A2), Spiroplasma apis (SR 3), and Spiroplasma melliferum (AS 576). Citrate synthase, aconitase, isocitrate dehydrogenase, α-ketoglutarate dehydrogenase, succinyl coenzyme A synthetase, succinate dehydrogenase, and fumarase were not detected in cell lysates of S. floricola (23-6). NADH oxidase and malate dehydrogenase were found in the cytosol whereas lactate dehydrogenase was loosely associated with the cytomembrane.Key words: spiroplasmas, osmotic lysis, tricarboxylic acid cycle, enzymes.

Serum Lactate Dehydrogenase Isoenzyme 1 and Relapse in Patients with Nonseminomatous Testicular Germ Cell Tumors Clinical Stage I

2001 ◽  
Vol 40 (4) ◽  
pp. 536-540 ◽  
Author(s):  
Finn Edler von Eyben ◽  
Ebbe Lindegaard Madsen ◽  
Ole Blaabjerg ◽  
Per Hyltoft Petersen ◽  
Hans von der Maase ◽  
...  
Keyword(s):  
Lactate Dehydrogenase ◽  
Germ Cell ◽  
Clinical Stage ◽  
Germ Cell Tumors ◽  
Serum Lactate ◽  
Stage I ◽  
Serum Lactate Dehydrogenase ◽  
Testicular Germ Cell Tumors ◽  
Testicular Germ Cell ◽  
Dehydrogenase Isoenzyme
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