Temperature-dependent enzyme kinetics during avian ontogeny: malate dehydrogenase in the common crow (Corvus brachyrhynchos) and the pintail (Anas acuta)

1973 ◽  
Vol 51 (6) ◽  
pp. 557-565 ◽  
Author(s):  
Michael Aleksiuk

The electrophoretic patterns and temperature-dependent kinetics of cytoplasmic malate dehydrogenase from liver of juvenile and adult representatives of the common crow (Corvus brachyrhynchos), an altricial species, and the pintail (Anus acuta), a precocial species, were examined. Starch gel electrophoresis revealed two major isoenzymes in each case. The isoenzymes of the juvenile and adult crow exhibit different electrophoretic mobilities, while those of the juvenile and adult pintail exhibit identical mobilities. Assay temperature has no statistically significant age-specific or species-specific effects on several kinetic properties of malate dehydrogenase. In all cases, the Michaelis constant (Km) of oxaloacetate for malate dehydrogenase remains fairly stable below 15 °C, but increases three- to four-fold from 15 ° to 45 °C. Values of activation energy vary between 12.1 and 15.0 kcal/mol. Q10 values for reaction velocities at minimum Km substrate levels are about 1.0 between 30° and 40 °C. The adaptive significance of the observed effects is discussed in relation to poikilothermic stages of the early posthatching ontogeny of birds.

Genetics ◽  
1973 ◽  
Vol 74 (4) ◽  
pp. 595-603
Author(s):  
D Borden ◽  
E T Miller ◽  
D L Nanney ◽  
G S Whitt

ABSTRACT The isozymic patterns of tyrosine aminotransferase, NADP malate dehydrogenase, NADP isocitrate dehydrogenase, and tetrazolium oxidase were examined by starch-gel electrophoresis in Tetrahymena pyriformis, syngen 1. The genetics of the alleles controlling these enzymes was studied through a breeding program. Each enzyme locus was shown to assort vegetatively, as do other loci in this organism. A detailed analysis of the assortment process for the tyrosine aminotransferase locus indicated that the rate of stabilization of heterozygotes into pure types was essentially identical to previously-reported rates for other loci.


1978 ◽  
Vol 68 (1) ◽  
pp. 85-97 ◽  
Author(s):  
S. J. Miles

AbstractThe genotypes of chromosomally-identified individuals from natural populations of the known species of the group of Anopheles gambiae Giles were scored for the enzyme protein structural loci coding for adenylate kinase (Adk), α-naphthyl acetate esterase (Est-1, Est-2, Est-3), glutamic-oxaloacetic transaminase (Got), α-glycerophosphate dehydrogenase (αGpd), hexokinase (Hk), isocitric dehydrogenase (Idh), lactic dehydrogenase (Ldh), ‘leucine’ aminopeptidase (Lap-2), malic enzyme (Me), octanol dehydrogenase (Odh), phosphoglucomutase (Pgm-1, Pgm-2), 6-phosphogluconic dehydrogenase (6-Pgd), phosphohexose isomerase (Phi) and superoxide dismutase (Sod), following starch gel electrophoresis. In the material examined, Est-1, Est-2, Est-3, Got, ldh, Lap-2, Odh, Pgm-1, Pgm-2 and Sod were segregating for two or more alleles; unique alleles at the Est-1, Got and Sod loci produced species-specific phenotypes in A. melas (Theo.), species C and species D, respectively. The further sampling of A. merus Dön, populations supported the presence of a unique SOD phenotype by which this species can also be identified. Of the other enzyme systems examined, no activity following electrophoresis was detected for aldolase and fructose-1,6-diphosphatase, and the resolution of acid and alkaline phosphatase, glyceraldehyde-3-phosphate dehydrogenase, glucose-6-phosphate dehydrogenase, malic dehydrogenase and xanthine dehydrogenase was too poor under the particular electrophoretic conditions for genetic analyses of the enzyme phenotypes.


1965 ◽  
Vol 13 (6) ◽  
pp. 510-514 ◽  
Author(s):  
JAMES L. CONKLIN ◽  
EDWARD J. NEBEL

Malate dehydrogenase fractions of the chick embryo were demonstrated after starch gel electrophoresis of homogenates of liver, brain and spleen. A total of seven malate dehydrogenase fractions were observed to occur in the chick embryo in an organ specific pattern. Treatment of the homogenates with urea, sodium chloride-sodium phosphate, and p-chloromercuribenzoate prior to electrophoresis revealed that only three distinct malate dehydrogenase-active proteins were presence. Two of these proteins exhibited properties similar to those previously reported for the supernatant malate dehydrogenase and mitochondrial malate dehydrogenase of other species. Becuase of the differing properties of chick malate and lactate dehydrogenase it is concluded that the molecular basis for malate dehydrogenase isozymes is different from that reported for lactate dehydrogenase isozymes.


1981 ◽  
Vol 34 (2) ◽  
pp. 149 ◽  
Author(s):  
K Bell ◽  
KE Hopper ◽  
HA McKenzie

An electrophoretic examination is made of milk samples taken from eight Bali (banteng) cattle, Bos (Bibos) javanicus, at Beatrice Hills, Northern Territory, Australia. Starch-gel electrophoresis at pH 8� 5 (NaOH-H3B03 buffer) and filter-paper electrophoresis at pH 8� 6 (diethylbarbiturate buffer) indicate that all samples contain a new a-lactalbumin variant, designated a-lactalbumin C. The order of mobility for bovine variants is A > B > C. The C variant differs from the common B variant in having one more amide residue (substitution of Asn for Asp or GIn for Glu).


1972 ◽  
Vol 50 (1) ◽  
pp. 9-15 ◽  
Author(s):  
D. J. Ecobichon

The cytoplasmic carboxylesterases of bovine, ovine, equine and human liver were fractionated by starch gel electrophoresis and by gel filtration on Sephadex. While species-specific, heterogeneous bands were observed in starch gel, the esterases of the bovine, ovine and equine liver were eluted from Sephadex G-100 as single peaks of activity, each with a characteristic elution volume. Gel filtration of human liver extracts yielded two peaks of activity, one containing electrophoretically slow esterases, the other electrophoretically fast esterases. Extracted equine and human hepatic carboxylesterases aggregated readily on storage or concentration, forming larger units which could be dissociated by a combination of acidic pH and high salt concentration. Molecular weight estimates of the hepatic esterases by gel filtration on Sephadex G-100 and G-200 yielded values of 65 000 for ovine, 55 000 for bovine, 96 000 and 70 000 for equine variants and 180 000 and 65 000 for human variants. The observations suggested that the cytoplasmic enzymes in relatively crude hepatic extracts had a lower molecular weight than those in concentrated or partially purified preparations which formed stable dimers or trimers.


1966 ◽  
Vol 23 (1) ◽  
pp. 101-107 ◽  
Author(s):  
H. Tsuyuki ◽  
E. Roberts

The species specific muscle myogens of Salmo gairdnerii, Oncorhynchus masou, O. masou ishikawae, O. kisutch, O. tshawytscha, O. keta, O. nerka, and O. gorbuscha are compared by starch gel electrophoresis. Plasma proteins of these same species are also examined by polyacrylamide disc electrophoresis. The range of usefulness of muscle myogens in species identification, and equally significantly, their value in establishing phylogenetic relationships of closely related groups, as the genus Oncorhynchus, are discussed. The myogen patterns of O. keta and O. gorbuscha from the Asiatic and North American coasts were found to be identical, further supporting the concept of absolute species specificity of these patterns.


1983 ◽  
Vol 215 (1) ◽  
pp. 213-216 ◽  
Author(s):  
R C Strange ◽  
P H Hirrell ◽  
G A Kitley ◽  
D A Hopkinson ◽  
W Cotton

Starch-gel electrophoresis was used to demonstrate two forms of glutathione S-transferase in human erythrocytes. Whereas considerable inter-individual differences in enzyme activity and electrophoretic patterns were detected, intra-individual differences were small.


1980 ◽  
Vol 192 (2) ◽  
pp. 649-658 ◽  
Author(s):  
S Passarella ◽  
E Marra ◽  
S Doonan ◽  
E Quagliariello

1. The mitochondrial malate dehydrogenase from rat liver has been purified to a state of homogeneity as judged by starch-gel electrophoresis and the cytoplasmic isoenzyme has been obtained in a partically purified state. 2. Inhibition of the isoenzymes by sulphite has been studied. 3. In mitochondria loaded with sulphite, the catalytic activity of the (partially inhibited) internal malate dehydrogenase has been measured by addition of oxaloacetate to the suspension medium and observation of the consequent decrease in fluorescence of NADH. 4. Addition of mitochondrial malate dehydrogenase to suspensions of mitochondria loaded with sulphite resulted in an increase in the level of intramitochondrial enzymic activity as measured by the above technique. Addition of the cytoplasmic isoenzyme did not result in such an increase. 5. These results show that mitochondria in suspension are permeable to the mitochondrial malate dehydrogenase but not to the cytoplasmic isoenzyme. 6. This conclusion has been confirmed by direct measurement of a decrease of enzyme activity in solution and an increase inside the mitochondria after incubation of organelles in solutions containing mitochondrial malate dehydrogenase. No such effect was observed with the cytoplasmic isoenzyme. 7. Some features of the permeation process have been studied.


1994 ◽  
Vol 68 (3) ◽  
pp. 181-186 ◽  
Author(s):  
T. Agatsuma ◽  
K. Terasaki ◽  
L. Yang ◽  
D. Blair

AbstractTwelve enzymes (encoded by 14 loci) in liver flukes of Fasciola species originating from Japan (parthenogenetic triploids), Korea (parthenogenetic diploids), the United States of America (USA) and Australia (all sexual diploids) were analysed using starch gel electrophoresis. Variation in electrophoretic patterns between samples was detected at five enzyme loci (Ak, Got, Gpi, 6-Pgd and Pgm-2). Japanese worms (31, of which six were established as uniparental laboratory strains), which reproduce by parthenogenesis, exhibited three different isozyme patterns. This indicates that triploidy has arisen more than once in Japanese flukes. Japanese Fasciola sp. can be separated into three types on morphological grounds. For the six laboratory strains of Japanese worms, the parental morphological type was known. Each of the three isozyme patterns observed was restricted to one morphological type. Most alleles detected in the Japanese triploids were also found in diploid worms from the other countries: the only alleles not represented elsewhere were four at the Got locus and two at the Pgm locus. Flukes from a laboratory strain derived from a single Korean diploid worm resembled the Japanese worms in genotype more closely than did American (seven uniparental laboratory strains) or Australian (30 worms) specimens. Worms from the last two countries were closely related.


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