Distribution of opine dehydrogenases and lactate dehydrogenase activities in marine animals

• 1.1. Opine dehydrogenases (OpDHs) and lactate dehydrogenase (LDH) activities were determined in various marine animals. OpDHs were detected in six marine invertebrate phyla; Porifera, Coelenterata, Annelida, Mollusca, Arthropoda and Echinodermata in phylogenic sequence.
• 2.2. Among several OpDHs, tauropine dehydrogenase (TaDH) occurred widely in marine invertebrates, from Porifera to Echinodermata.
• 3.3. With a few exceptions, total OpDHs activities exceeded that of LDH activity in the marine invertebrates investigated.
• 4.4. With respect to anaerobic glycolysis, OpDHs are indicated to play an important role in phylogenically lower invertebrates, whereas LDH is more important in higher animals.

     

Enzyme activities and level of SH groups in breast carcinomas

• 1.1. The carcinoma showed higher enzyme activities than the normal mammary tissue.
• 2.2. The ratios of glutamate dehydrogenase, glutathione reductase and catalase to lactate dehydrogenase were lower in carcinomas than in normal tissues. Similarly, the ratios of glutamate dehydrogenase, glutathione reductase and catalase to glucose-6-phosphate dehydrogenase were also significantly lower in carcinomas.
• 3.3. There were no significant differences in enzyme activities between stages I and II of disease, however in the metastatic tissues, there were significant differences between stages I and II.
• 4.4. SH groups were higher in the tissues of cancer patients than in normal tissues. The levels of thiols groups were higher in carcinomas at stage III of disease.

     

Distribution of beta-adrenergic binding in fractionated porcine adipocytes

• 1.1. The subcellular distribution of the porcine adipocyte beta-adrenergic receptor was studied in fractionated adipocytes.
• 2.2. The 30,000 g pellet obtained from hypotonically lysed cells contained membrane vesicles and mitochondria; it yielded approx 200–300 fmol dihydroalprenolol-bound receptors/mg protein.
• 3.3. Activity was increased to about 1000 fmol/mg protein after isolation of a plasma membrane fraction on a Percoll gradient.
• 4.4. The 5'-nucleotidase, succinate dehydrogenase and lactate dehydrogenase activities were usually enriched in compartments different from the ligand-binding activity.
• 5.5. Activity of porcine adipocyte 5'-nucleotidase, a purported plasma membrane marker enzyme, was not distributed in the same manner as the beta-adrenergic receptor.

     

Role of glutamate dehydrogenase reaction in the control of citrate pool in yeast

• 1.1. Role of NADP-glutamate dehydrogenase in the depletion of citrate was analyzed using permeabilized yeast cells.
• 2.2. Citrate was converted to 2-oxoglutarate, which was then metabolized to glutamate by NADP-glutamate dehydrogenase in the presence of ammonium ion.
• 3.3. Formation of 2-oxoglutarate plus glutamate was in good agreement with the concentration of citrate decreased. Glutamate formation can be a good indicator of the depletion of citrate, because 70% of the citrate decreased was converted to glutamate.
• 4.4. Glycolytic activity was closely correlated with the decrease in citrate under the in situ conditions.
• 5.5. NADP-glutamate dehydrogenase increased in anaerobically grown yeast cells.
• 6.6. An effective depletion of citrate by increased synthesis of NADP-glutamate dehydrogenase can explain the lowered mechanism of citrate causing glycolytic stimulation under the anaerobic growth conditions of yeast.

     

A comparative study of the basic nuclear proteins from sperm of bivalve molluscs

• 1.1. Basic nuclear proteins from spermatozoa of the three mollusc species belonging to the class Bivalvia have been analyzed using one- and two-dimensional electrophoresis.
• 2.2. Four nuclear basic proteins have been purified and their amino acid compositions determined.
• 3.3. In these spermatozoa histone-type proteins coexist with protamine-like proteins.
• 4.4. The protamine-like proteins that have been studied show different electrophoretic behavior but in general are similar, with a high content of lysine, arginine, alanine and serine.
• 5.5. Interspecific variability has been found for the H1-like histone.

     

Electrophoretic characterization of a hybrid between Eretmochelys imbricata and Caretta caretta (Cheloniidae)

• 1.1. An intermediate morphotype between Eretmochelys imbricata and Caretta caretta was studied in Praia do Forte, Bahia, Brazil.
• 2.2. Three enzymatic systems were successfully analyzed: SOD, lactate dehydrogenase (LDH) and esterase (EST). Isoelectric focusing of total soluble proteins of muscle and transferrin were shown.
• 3.3. Esterase exhibited nine phenotype patterns, seven in C. caretta and one in the others morphotypes. SOD phenotypes were identical in the three morphotypes. Lactate dehydrogenase and transferrins were characteristic for each species.
• 4.4. Jaccard's measure of similarity was calculated and a phenogram with the three morphotypes were constructed using isoelectric focusing of total soluble proteins.

     

Light-induced effects of several enzymes of carbohydrate metabolism in Phycomyces blakesleeanus

• 1.1. The photoregulation shown by glyceraldehyde 3-phosphate dehydrogenase and glucose 6-phosphate dehydrogenase appears to be independent of the mad gene product(s) and also independent of carotene biosynthesis regulation.
• 2.2. The photoregulation of malate dehydrogenase appeared to be dependent on the mutation of the mad and car S genes.
• 3.3. Pyruvate kinase and lactate dehydrogenase may be classified as light-independent.
• 4.4. The action of ATP and fructose 1,6-bisphosphate on the enzymes studied was generally independent of light/dark grown conditions.
• 5.5. However, the effect of fructose 1,6-bisphosphate on Phycomyces pyruvate kinase appears to be light-dependent.

     

Further studies on the phylogenetic distribution of pyruvate oxidoreductase activities

• 1.1. The phylogenetic distribution of lactate, octopine, alanopine and strombine dehydrogenase activities (respectively, LDH, ODH, ADH and SDH) was examined in over 60 species from seven phyla and from three continents.
• 2.2. The results confirm and extend previously published data. Consistencies of distribution are observed at the levels of phyla, class, order and family.
• 3.3. Major observations include prominent SDH in the Porifera; LDH only in the Polyplacophera, Nudibranchia and Myidae (Mollusca) and nereid worms (Polychaeta); ODH and SDH in the marine pulmonate Melampus bidentatus (Basommatophora); high ADH to SDH ratios in marine gastropods; high ODH in active molluscs; and apparent SDH in the barnacle Lepas anatifera.
• 4.4. The results are discussed in relation to theories of opine pathway evolution and the newly discovered tauropine and β-alanopine opine dehydrogenases.

     

The effects of oxalate and glucose on lipogenesis by isolated hepatocytes from normal and biotin-deficient chicks (Gallus domesticus)

• 1.1. Isolated hepatocytes synthesize fatty acids and cholesterol from lactate and acetate with lactate being the more effective substrate.
• 2.2. Biotin deficiency decreased fatty add synthesis from both substrates but stimulated cholesterogenesis.
• 3.3. Exposure of intact hepatocytes to oxalate inhibited fatty acid and cholesterol synthesis from lactate, this effect was enhanced in biotin-deficient chicks. A similar effect was not observed when acetate was the substrate.
• 4.4. Synthesis of fatty acids from lactate and acetate was stimulated by glucose, biotin deficiency increased this response. Cholesterogenesis was reduced in control but not biotin-deficient chicks.

     

Agaricus bisporus tyrosinase—II. Characterization of hydroxylase and dehydrogenase activities

• 1.1. Preparative Isoelectric focusing (PIEF) was used to isolate hydroxylasic and dehydrogenasic activities, at different pI.
• 2.2. The fraction at pI 4.7 and 4.9 displays a pure dehydrogenase activity (substrate l-DOPA).
• 3.3. This fraction did not react with tyrosine, either in the spot-test or in absorption spectra (200–620 nm), and did not exhibit any oxygen consumption.
• 4.4. The fraction at pI 4.1 and 4.3 reacted with both l-DOPA and tyrosine as substrate, showing dehydrogenase and hydroxylase activity.
• 5.5. The latter activity was confirmed by the oxygen consumption test, showing that molecular oxygen is used to ortho-hydroxylate tyrosine.

     

A halogenated amino acid-containing sperm activating peptide and its related peptides isolated from the egg jelly of sea urchins,Tripneustes gratilla,Pseudoboletia maculata,Strongylocentrotus nudus,Echinometra mathaei and Heterocentrotus mammillatus

• 1.1. Twenty-eight peptides were isolated from the egg jelly of sea urchins, Tripneustes gratilla, Pseudoboletia maculata, Strongylocentrotus nudus, Echinometra mathaei (type A and B) and Heterocentrotus mammillatus and their amino acid sequences were determined.
• 2.2. Two of the peptides obtained from T. gratilla egg jelly possessed a bromophenylalanine (Br-Phe) residue in their sequences (Gly-(Br-Phe)-Asn-Leu-Asn-Gly-Gly-Gly-Val-Gly and Gly-(Br-Phe)-Asp-Leu-Asn-Gly-Gly-Gly-Val-Gly).
• 3.3. All of the peptides elevated cyclic GMP concentrations in the spermatozoa of the respective sea urchin and caused a shift in the apparent mol. wt of a major sperm protein of the respective sea urchin.
• 4.4. They stimulated respiration rates of the spermatozoa of Hemicentrotus pulcherrimus as well as their own species.
• 5.5. One-half maximal concentrations of the peptides for respiratory stimulation of H. pulcherrimus spermatozoa were between 10⁻¹¹ M and 10⁻⁹ M except a methionine-containing peptide which was about 10⁻⁷ M.

     

Metabolic and contractile differentiation of rabbit muscles during growth

• 1.1. A study was carried out of post-natal evolution of the oxidative, glycolytic and contractile capacities in various types of rabbit muscle.
• 2.2. At birth, muscles are non-differentiated and present very limited metabolic and contractile activity, metabolism is mainly oxidative in all muscles.
• 3.3. Although muscular discrimination is manifest from the sixth week after birth, the glycolytic metabolism reaches its maximum capacity only after six to eight weeks.
• 4.4. Subsequently, oxidative metabolic capacity steadily decreases until adulthood.

     

Changes in plasma glucose and lipid concentrations during treadmill exercise in domestic fowl

• 1.1. Plasma glucose, non-esterified fatty acid, triglyceride, cholesterol and lactate concentrations were measured during 90 min treadmill exercise at a work intensity of 55–60% maximum.
• 2.2. After 90 min exercise plasma glucose fell by 35% whilst the non-esterified fatty acid concentration rose to as much as 3–4 times resting.
• 3.3. Exercise had no significant effect on plasma cholesterol, triglyceride or lactate concentrations.
• 4.4. The findings indicate a progressive increase in fat utilization during prolonged exercise. Possible hormonal mechanisms underlying exercise-induced changes in lipid and carbohydrate metabolism are discussed.

     

One and two dimensional isoelectric focusing of lactate dehydrogenase from the tissues of Ovis aries

• 1.1. Lactate dehydrogenase in ovine tissues was separated by electrophoresis, one dimensional isoelectric focusing (IEF) and a two dimensional technique.
• 2.2. Tissues showed five zones of enzyme activity consisting of multiple bands after IEF.
• 3.3. The IEF zymograms were unique for each tissue and differed from those of other species.
• 4.4. Two dimensional separation revealed that the five zones of activity observed on IEF corresponded to the five isoenzymes separable by conventional electrophoresis.

     

Adenosine effect on lactate and pyruvate production in the hypoxic guineapig heart

• 1.1. It has been shown that adenosine stimulates glycolysis in some cells and this ability of adenosine was tested in the hypoxic guineapig heart.
• 2.2. Adenosine (10 μM) activated lactate production in the isolated perfused guineapig heart under conditions of normoxia but did not under hypoxia.
• 3.3. Despite this, the nucleoside favorably influenced the energy metabolism of the hypoxic heart as revealed by the better posthypoxic functional recovery (98%) compared to the control without adenosine (78%).
• 4.4. Our findings suggest a role for the glycolytic pathway in this effect of the nucleoside as long as other cardiac energy-yielding pathways are strictly aerobic.

     

A one-step pmr determination of hydrogen transfer stereospecificity of NADP+-linked oxidoreductases

• 1.1. A simple, facile one-step method has been devised to measure the stereospecificity of NADP⁺-linked oxidoreductases. The procedure involves coupling the test enzymes to enzymes of known stereospecificity in the presence of deuterated substrates. The regenerated NADP⁺ in the coupled reactions is analyzed by PMR for its deuterium content at the carbon-4 position of the nicotinamide ring.
• 2.2. It is found that malate dehydrogenase (EC 1.1.1.37). lactate dehydrogenase (EC 1.1.1.27) and glycerate dehydrogenase (EC 1.1.1.29) are A-side stereospecific whereas glutamate dehydrogenase (EC 1.4.1.3) and glycerol-3-phosphate dehydrogenase (EC 1.1.1.8) are B-side stereospecific.
• 3.3. Enzymes which can utilize both NAD⁺ and NADP⁺ have the same stereospecificity with respect to the coenzyme.

     

The Proteome of Pig Spermatozoa Is Remodeled During Ejaculation

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Highlights

• •Proteome of mature boar spermatozoa from cauda epididymal and ejaculated sources were analyzed by iTRAQ-based LC-MS/MS.
• •1,723 sperm proteins identified (974 of Sus scrofa taxonomy).
• •1,602 sperm proteins quantified (960 of Sus scrofa taxonomy).
• •32 Sus scrofa sperm proteins were differentially expressed among sperm sources.
• •The proteome of boar spermatozoa is remodelled during ejaculation.

     

The effect of prolonged fasting on total lipid synthesis and enzyme activities in the liver of the European eel (Anguilla anguilla)

• 1.1. The extent of fatty acid synthesis from [1-¹⁴C]acetate in liver slices was reduced 6-fold when eels were fasted for 1–7 weeks and 20-fold when fasted for 39 weeks; thereafter hepatic lipogenesis seemed to remain constant for up to 95 weeks of fasting.
• 2.2. After a 1–3 week fast some hepatic enzyme activities were reduced (acetyl-CoA carboxylase decreased 2-fold and fatty acid synthetase declined 5-fold), while others remained unchanged (glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, α-glycerol phosphate dehydrogenase as well as malic enzyme and ATP-citrate lyase).
• 3.3. The optimum temperature for measuring both total lipid synthesis and lipogenic enzyme activity in eel liver was found to be 30°C.

     

Interaction of lipogenic substrates in porcine adipose tissue in vitro

• 1.1. Porcine adipose tissue was incubated with radiolabeled glucose, acetate or lactate. Saturation curves indicated that lactate > glucose > acetate in providing two-carbon units for fatty-acid synthesis.
• 2.2. Competition between individual substrates indicated that lactate was the best lipogenic substrate.
• 3.3. Incubation of all three substrates at concentrations observable in serum indicated that at 5.56mM, glucose was the preferred lipogenic substrate in the presence of 0.1 mM acetate and 1.0 mM lactate.
• 4.4. At elevated concentrations (18.52mM glucose, 1.0 mM acetate and 10.0 mM lactate), acetate and lactate were preferred to glucose as lipogenic substrates.