scholarly journals Malate dehydrogenases in phototrophic purple bacteria. Thermal stability, amino acid composition and immunological properties

1988 ◽  
Vol 252 (2) ◽  
pp. 595-600 ◽  
Author(s):  
M A Tayeh ◽  
M T Madigan
Keyword(s):  
Amino Acid ◽  
Amino Acid Composition ◽  
Malate Dehydrogenase ◽  
Acid Composition ◽  
Rhodospirillum Rubrum ◽  
Rhodobacter Capsulatus ◽  
Purple Bacteria ◽  
Heat Stability ◽  
Heat Stable ◽  
Rhodomicrobium Vannielii

Purified malate dehydrogenases from four species of non-sulphur purple phototrophic bacteria were examined for their heat-stability, amino acid composition and antigenic relationships. Malate dehydrogenase from Rhodospirillum rubrum, Rhodobacter capsulatus and Rhodomicrobium vannielii (which are all tetrameric proteins) had an unusually high glycine content, but the enzyme from Rhodocyclus purpureus (which is a dimer) did not. R. rubrum malate dehydrogenase was extremely heat-stable relative to the other enzymes, withstanding 65 degrees C for over 1 h with no loss of activity. By contrast, malate dehydrogenase from R. vannielii lost activity above 35 degrees C, and that from R. capsulatus above 40 degrees C. Amino acid compositional relatedness and immunological studies indicated that tetrameric phototrophic-bacterial malate dehydrogenases were highly related to one another, but only distantly related to the tetrameric enzyme from Bacillus. This suggests that, despite differences in their thermal properties, the tetrameric malate dehydrogenases of non-sulphur purple bacteria constitute a distinct biochemical class of this catalyst.

Multiple molecular forms of avian aldolases. II. Enzymic properties and amino acid composition of chicken (Gattus domesticus) breast muscle aldolase

1969 ◽  
Vol 47 (5) ◽  
pp. 527-534 ◽  
Author(s):  
Ronald R. Marquardt
Keyword(s):  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Heat Stability ◽  
Breast Muscle ◽  
Molecular Forms ◽  
Ph Optimum ◽  
Wide Ph Range ◽  
Michaelis Constants ◽  
Ph Range

Several properties of crystalline chicken (Gallus domesticus) breast muscle aldolase (fructose 1,6-diphosphate–D-glyceraldehyde 3-phosphate lyase, EC 4.1.2.13) were determined. The enzyme was found to have a broad pH optimum centered around pH 7.1 and to be remarkably stable over a wide pH range. The temperature coefficient Q10 is 2.6 in the range from 10 to 35 °C. The enzyme is stable at 48 °C for 10 min and almost completely inactivated at 55 °C. The apparent Michaelis constants for fructose 1,6-diphosphate and fructose 1-phosphate were 4.2 × 10−5 M and 1.7 × 10−2 M, respectively. The phosphate inhibitor constant (K1) was 5.5 × 10−3 M.Chicken breast muscle aldolase is similar to the rabbit enzyme in many of the above properties, although there are significant differences in heat stability and amino acid composition.

scholarly journals A reappraisal of some structural features of bovine heart malate dehydrogenase

1968 ◽  
Vol 109 (4) ◽  
pp. 663-668 ◽  
Author(s):  
Elizabeth Heyde ◽  
S. Ainsworth
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Malate Dehydrogenase ◽  
Acid Composition ◽  
Diffusion Coefficients ◽  
Structural Features ◽  
Similar Data ◽  
Bovine Heart ◽  
And Diffusion

1. Malate dehydrogenase of the mitochondrial type was prepared from an acetone-prepared powder of thoroughly washed minces of whole bovine heart by previously reported methods that were modified to give higher yields of the purified enzyme. 2. Determinations of the sedimentation and diffusion coefficients showed the molecular weight of the enzyme to be approx. 63000. The amino acid composition of the enzyme was also determined. Discrepancies between these data and similar data previously reported by Davies & Kun (1957) and Siegel & Englard (1962) were resolved. 3. ‘Fingerprints’ were made from tryptic digests of heat-denatured and of reduced and alkylated enzyme. These indicated that the enzyme is composed of a number of identical or similar sub-units.

Effect of maternal diet on the amino acid composition of human uterine fluid

2014 ◽  
Author(s):  
Alexandra Jayne Kermack ◽  
Ying Cheong ◽  
Nick Brook ◽  
Nick Macklon ◽  
Franchesca D Houghton
Keyword(s):  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Maternal Diet ◽  
Uterine Fluid
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