L-Lactate dehydrogenases

L-lactate dehydrogenase semm differentiation of heart cell damage... 

L-Lactate dehydrogenase is a tetrameric enzyme whose four subunits occur in two isoforms, designated H (for... 

White blood cell count greater than 50 x 103/pL (50 x 109/L) Lactate dehydrogenase (LDH) levels greater than 1500 IU/L (1500 U/L or 25 uKat/L)... 

The deracemization of lactate, in principle, is also interesting. In this process, pyruvate is reduced at the cathode to racemic lactate which is reoxidized to pyruvate by the cheap L-lactate dehydrogenase combined with the anodic... 

Fig. 5. Coupled electrochemical process for the formation of D-lactate from pyruvate (l-LDH = L-lactate dehydrogenase)...

L-lactate dehydrogenase from rabbit muscle (E.C. 1.1.1.27) (25 units) methanol (analytical grade) methylene chloride (analytical grade)... 

The concentration of hydroxypyruvate was determined by spectrophotometry at 340 nm. A 20 pL aliquot from the reaction mixture was introduced into 1 mL of triethanolamine buffer (0.1 m) at pH 7.6 containing 20 /rL of NADH solution in water (14 mm, 0.28 /imol) and 2 units of L-lactate dehydrogenase. The absorbance due to NADH is proportional to the concentration of hydroxypyruvate. 

CYTOCHROME P-450 REDUCTASE DIHYDROOROTATE OXIDASE FMN ADENYLYLTRANSFERASE GLUTAMATE SYNTHASE GLYCOLATE OXIDASE (S)-2-HYDROXY-ACID OXIDASE l-LACTATE DEHYDROGENASE (CYTOCHROME)... 

The advantage of this reaction is that lactate is mnch cheaper than pyruvate, so the reaction is not only useful for the regeneration of NADH but also for the production of pyruvate. The disadvantage is that lactate dehydrogenases are enantiospecific, so a D-lactate as well as an L-lactate dehydrogenase are reqnired for a full conversion of racemic lactate (Figure 10.7). 

L-Lactate dehydrogenase catalyzes the reversible oxidation of L-lactate to pyruvate, using NAD+ as a coenzyme (equation 16.5). 

The characteristic stereospecificity of enzymes has been exploited in the design of an electrochemical cell for the conversion of L-lactate to D-lactate (Scheme 23)117. Enzymatic oxidation of L-lactate by L-lactate dehydrogenase affords pyruvate. Pyruvate is then reduced electrochemically to racemic lactate. A second enzymatic oxidation of the latter by L-lactate dehydrogenase selectively converts L-lactate to pyruvate, leaving D-lactate behind. The ingenious feature of this system is the fact that pyruvate can be re-reduced... 

Kwan et al. [27] l-Lactate Yoghurt milk, soda, sport drinks, and healthy supplement Salicylate hydroxylase (SHL), L-lactate dehydrogenase (LDH), and pyruvate oxidase (PyOD)/entrapped by a poly(carbamoyl) sulfonate (PCS) hydrogel on a Teflon membrane Clark-type oxygen electrode ... 

Lobo-Castanon et al. [23] L- Lactate Cider Glutamic pyruvic transaminase (GPT) and l-lactate dehydrogenase (LDH) together with NAD+/by an electropolymerised poly-(o-phenylenediamine) (PPD) film Carbon paste modified with PPD and poly(o-aminophenol)/0 V vs. Ag/AgCl ... 

Katrlik et al. [63] L-Malate, l-lactate Wines L-Malate dehydrogenase or l-lactate dehydrogenase and diaphorase/covered by a dialysis membrane NAD+-modified graphite-2-hexadecanone composite electrode Hexacyanoferrate(III)... 

Sulfite modified enzyme electrode. (2) L-Lactate/L-malate/ sulfite multibiosensor L-lactate dehydrogenase/L-malate dehydrogenase/ sulfite oxidase surface-modified enzyme electrodes/enzymes were deposited on the composite electrodes and covered with a dialysis membrane ... 

N. Holmberg, U. Ryde, and L.Bulow, Redesign of the coenzyme specificity in L-lactate dehydrogenase from Bacillus stearothermophilus using site-directed mutagenesis and media engineering,... 

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