Glutamate Dehydrogenase of Pisum sativum: Heat-Dependent Interconversion of the Multiple Forms

1984 ◽  
Vol 39 (3-4) ◽  
pp. 257-260 ◽  
Author(s):  
Adelheid Ehmke ◽  
Heinz-Walter Scheid ◽  
Thomas Hartmann
Keyword(s):  
Glutamate Dehydrogenase ◽  
Direct Evidence ◽  
Molecular Forms ◽  
Stable Form ◽  
Protein Species ◽  
Multiple Forms ◽  
Single Protein ◽  
Catalytically Active ◽  
Pea Seeds ◽  
The Individual

Purified NAD-dependent glutamate dehydrogenase (EC 1.4.1.2) from pea seeds shows a pattern of seven catalytically active molecular forms. The individual forms display different heat stabilities. During incubation at 70 to 75 °C in the presence of protective agents (NADH, Ca2+, DTE) the more heat labile forms are converted into the most stable form. This result presents direct evidence that the multiple forms of pea glutamate dehydrogenase represent conform ational variants of a single protein species

Biochemical Markers in the Family Canidae.

1975 ◽  
Vol 23 (3) ◽  
pp. 411 ◽  
Author(s):  
P Clark ◽  
GE Ryan ◽  
AB Czuppon
Keyword(s):  
Genetic Markers ◽  
Biochemical Markers ◽  
Domestic Dogs ◽  
Marked Variation ◽  
Glucosephosphate Isomerase ◽  
Protein Species ◽  
Multiple Forms ◽  
The Family ◽  
Single Protein ◽  
High Degree

One quantitative and nine qualitative genetic markers were investigated in some 200 individuals of the family Canidae, including 34 breeds and species. A high degree of homogeneity was observed and only one marker, transferrin, displayed marked variation. The consistent differences were: wolf (one sample), transferrin; jackal (one sample), transferrin and glucosephosphate isomerase; foxes, albumin, transferrin and glucosephsophate isomerase. Two abnormal transferrins were observed in two siblings among six German short-haired pointers. All other markers were homogeneous, usually single protein species or multiple forms dispersed randomly through the group. The results suggest that domestic dogs and dingoes share a common pool of genes and that all canids but the foxes possess many genes in common. There are indications that the jackal and wolf may differ from other canids in some marker systems.

scholarly journals Human oxygenase variants employing a single protein Fe(II) ligand are catalytically active

2021 ◽  
Author(s):  
Amelia Brasnett ◽  
Inga Pfeffer ◽  
Lennart Brewitz ◽  
Rasheduzzaman Chowdhury ◽  
Yu Nakashima ◽  
...  
Keyword(s):  
Single Protein ◽  
Catalytically Active

scholarly journals Human oxygenase variants employing a single protein Fe(II) ligand are catalytically active

2021 ◽  
Author(s):  
Amelia Brasnett ◽  
Inga Pfeffer ◽  
Lennart Brewitz ◽  
Rasheduzzaman Chowdhury ◽  
Yu Nakashima ◽  
...  
Keyword(s):  
Single Protein ◽  
Catalytically Active

scholarly journals The distribution of phospholipase D in developing and mature plants

1969 ◽  
Vol 112 (5) ◽  
pp. 787-794 ◽  
Author(s):  
R. H. Quarles ◽  
R. M. C. Dawson
Keyword(s):  
Phospholipase D ◽  
Dry Weight ◽  
Total Activity ◽  
Weight Basis ◽  
Carrot Root ◽  
Aerial Parts ◽  
Central Stalk ◽  
Pea Seeds ◽  
The Individual ◽  
Germination And Growth

1. The distribution of phospholipase D (phosphatidylcholine phosphatido-hydrolase, EC 3.1.4.4) was examined in the tissues of a number of plants and seeds. 2. The highest activities were found in various swollen storage tissues of certain plants: cabbage, central stalk; cauliflower, flower; celery, swollen leaf stalk; Kohl rabi, swollen stem; carrot, root; pea and marrow, seed. 3. Appreciable activity was retained in pea seeds for at least 1 year after drying. After germination and growth in the dark the total activity present in the cotyledons and also in the whole seedling decreased. 4. In the growing pea seedling (7 days old), about 3% of the total activity was in the plumule, 9% in the root and the remainder in the cotyledons. However, the activity in the root on a dry-weight basis was higher than that in the cotyledons. In both the root and the plumule the activity on a wet- or a dry-weight basis was highest in the growing tip. 5. The activity per dry weight in the roots and aerial parts of pea plants declined to low values as growth continued, but roots struck from cuttings of mature plants showed the same high activity as found in roots from young seedlings with cotyledons attached. 6. The total phospholipids present in the cotyledons of pea seeds were depleted on germination and growth. Of the individual phospholipids, phosphatidylcholine and phosphatidylethanolamine showed the same loss in 11 days as the whole phospholipid fraction, whereas phosphatidylinositol was decreased to a greater extent and cardiolipin and phosphatidylserine were not decreased. There was no increase of phosphatidic acid, as might have been expected if the phospholipids had disappeared through phospholipase D hydrolysis. 7. It is concluded that phospholipase D in plant storage tissues and seeds may be related to the rapid growth involved in their formation rather than being necessary for the utilization of their food reserve substances.

A single frizzled protein has a dual function in tissue polarity

Development ◽  
1994 ◽  
Vol 120 (7) ◽  
pp. 1883-1893 ◽  
Author(s):  
R.E. Krasnow ◽  
P.N. Adler
Keyword(s):  
Dual Function ◽  
Protein Species ◽  
Hsp70 Promoter ◽  
Tissue Polarity ◽  
Genetic Mosaic ◽  
Single Protein ◽  
Genetic Epistasis ◽  
Pupal Wing ◽  
Separate Protein ◽  
Transgenic Flies

The Drosophila frizzled (fz) gene is required for the development of normal tissue polarity in the epidermis. Genetic epistasis experiments argue that fz is at the top of a regulatory hierarchy that controls the subcellular site for prehair initiation within the cells of the pupal wing (Wong and Adler, 1993; J. Cell Biol. 123, 209–221). Genetic mosaic experiments indicate that fz has both cell autonomous and cell non-autonomous functions that are separately mutable (Vinson and Adler, 1987; Nature 329, 549–551). Two species of fz mRNA have been identified, raising the question as to whether the two functions are provided by a single protein or by two separate protein species. We generated transgenic flies that express each of these mRNAs under the control of an hsp70 promoter. Only one of the transgenes (hsfzI) showed any fz activity. At 29 degrees C, the hsfzI transgene provided almost complete rescue of a null fz mutation, indicating that the protein encoded by this cDNA can fulfill both fz functions. Overexpression of the hsfzI transgene resulted in two distinct tissue polarity phenotypes depending on the time of heat shock.

Back to the future-The value of single protein species investigations

PROTEOMICS ◽  
2013 ◽  
Vol 13 (21) ◽  
pp. 3103-3105 ◽  
Author(s):  
Peter R. Jungblut
Keyword(s):  
Protein Species ◽  
Single Protein ◽  
The Future

scholarly journals Posttranslational Modifications and the Immunogenicity of Biotherapeutics

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Roy Jefferis
Keyword(s):  
Posttranslational Modifications ◽  
Drug Product ◽  
Molecular Forms ◽  
Phagocytic Cells ◽  
Production Platform ◽  
The Individual ◽  
And Function ◽  
Antigen Presenting

Whilst the amino acid sequence of a protein is determined by its gene sequence, the final structure and function are determined by posttranslational modifications (PTMs), including quality control (QC) in the endoplasmic reticulum (ER) and during passage through the Golgi apparatus. These processes are species and cell specific and challenge the biopharmaceutical industry when developing a production platform for the generation of recombinant biologic therapeutics. Proteins and glycoproteins are also subject to chemical modifications (CMs) bothin vivoandin vitro. The individual is naturally tolerant to molecular forms of self-molecules but nonself variants can provoke an immune response with the generation of anti-drug antibodies (ADA); aggregated forms can exhibit enhanced immunogenicity and QC procedures are developed to avoid or remove them. Monoclonal antibody therapeutics (mAbs) are a special case because their purpose is to bind the target, with the formation of immune complexes (ICs), a particular form of aggregate. Such ICs may be removed by phagocytic cells that have antigen presenting capacity. These considerations may frustrate the possibility of ameliorating the immunogenicity of mAbs by rigorous exclusion of aggregates from drug product. Alternate strategies for inducing immunosuppression or tolerance are discussed.

Glutamate Dehydrogenase from Pea Roots: Purification and Properties of the Enzyme

1971 ◽  
Vol 49 (1) ◽  
pp. 127-138 ◽  
Author(s):  
E. Pahlich ◽  
K. W. Joy
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Glutamate Dehydrogenase ◽  
Constant Ratio ◽  
Ph Optimum ◽  
Purification And Properties ◽  
Activity Ratios ◽  
Single Protein ◽  
Michaelis Constants ◽  
Pea Roots

Glutamate dehydrogenase (L-glutamate: NAD+ oxidoreductase (deaminating), EC 1.4.1.2) has been purified 1250-fold from pea roots. The preparation contains only a single protein, and the molecular weight was estimated to be 208 000 ± 10 000. The enzyme shows NADH (aminating) and NAD+ (deaminating) activities, but the ratio of these activities is not constant and can be changed experimentally. NADPH activity is also present and shows a relatively constant ratio to NAD+ activity. EDTA inhibits NADH activity in intermediate concentrations, but reactivates at higher concentrations. NAD+ (and NADPH) activity is only slightly changed by EDTA. The effects of dioxane and the coenzymes on the enzyme are also reported. Mechanisms which could explain the different activity ratios, in terms of two interconvertible enzyme forms, are discussed.The pH optimum for NADH and NAD+ activities is about pH 8.0. Michaelis constants were found to be: α-ketoglutarate, 3.3 × 10−3 M; ammonium (sulfate), 3.8 × 10−2 M; glutamate, 7.3 × 10−3 M; NADH, 8.6 × 10−4 M; NAD+, 6.5 × 10−4 M. The enzyme is highly specific for the substrates glutamate and α-ketoglutarate, showing no alanine or aspartate dehydrogenase activity, and no deamination with a range of amino acids.

scholarly journals The allosteric mechanism of bovine liver glutamate dehydrogenase. Evidence from circular-dichroism studies for a conformational change in the ternary complex enzyme-(oxidized nicotinamide-adenine dinucleotide)-glutarate

1977 ◽  
Vol 163 (2) ◽  
pp. 297-302 ◽  
Author(s):  
S S Chen ◽  
P C Engel ◽  
P M Bayley
Keyword(s):  
Circular Dichroism ◽  
Glutamate Dehydrogenase ◽  
Conformational Change ◽  
Circular Dichroism Spectrum ◽  
Direct Evidence ◽  
Bovine Liver ◽  
Substrate Analogues ◽  
Allosteric Mechanism ◽  
Nad 4 ◽  
Circular Dichroïsm

1. Computer averaging of multiple scans was used to refine the circular dichroism spectrum of bovine liver glutamate dehydrogenase, revealing well-defined structure in the aromatic region. 2. The circular dichroism of NAD+ bound to glutamate dehydrogenase is strongly negative at 260nm, probably owing to immobilization of the adenosine moiety. Loss of the characteristic adenine-nicotinamide interaction suggests that the coenzyme is bound in an unstacked conformation. 3. Glutarate and succinate, substrate analogues that are both inhibitors competitive with glutamate, do not significantly perturb the circular-dichroism spectrum of the enzyme in the absence of NAD+. 4. In the presence of NAD+, 150nM-succinate decreases the negative circular dichroism corresponding to bound coenzyme, but does not affect the protein circular dichroism. However, ISOmM-glutarate causes profound alternations of the circular-dichroism spectra of the bound NAD+ and of the enzyme, indicative of a protein conformational change. This direct evidence of conformational change specifically promoted by C5 dicarboxylates confirms the previous inference from protection studies. 5. The conformational change is discussed in relation to the allosteric mechanism of glutamate dehydrogenase.

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