Search results for "Storage protein"
showing 7 items of 27 documents
A pea nuclear protein that is induced by dehydration belongs to the vicilin superfamily
2000
The purification to homogeneity of p16, a protein with an electrophoretic mobility compatible with an apparent molecular mass of 16 kDa, from nuclei of ungerminated pea embryonic axes is described. A cDNA clone of its gene, which was designated psp54, was also isolated. The psp54 cDNA contains an open reading frame coding for a 54.4-kDa polypeptide (p54). p16 corresponds to the C-terminal third of p54, although the mechanisms by which the primary polypeptide could be processed are not yet known. The sequence of p54 is 60% identical with that of the precursor of a sucrose-binding soybean protein, and, to a lesser extent (31-34%), it shares homology with some storage proteins. p16 is also 30%…
Localization and Activity of a Carboxypeptidase in Germinating Seeds of Scots Pine, Pinus sylvestris
1976
Extracts prepared from the endosperm of germinating seeds of Scots pine, Pinus sylvestris L., hydrolysed two typical carboxypeptidase substrates, Z-Phe-Ala and Z-Phe-Phe, with pH optima at 4.2 and 5.0. The activities were completely destroyed by diisopropylfluorophosphate. Identical heat inactivation curves and elution patterns in gel chromatography on Sephadex G-200 suggest that the two activities are due to a single enzyme. In resting seeds very low carboxypeptidase activity was present in both the endosperm and the embryo. During germination on agar gel at 20°C in the dark the activities, expressed as enzyme units per seed, increased in the seedling and particularly in the endosperm up t…
Characterization of the Proteinases Present in Germinating Seeds of Scots Pine, Pinus sylvestris
1978
Methods were developed to determine proteinase activity in germinating seeds of Scots pine. The assays were based on the liberation of TCA-soluble peptides from haemoglobin at pH 3.7 and from casein at pH 5.4 and pH 7.0; the reaction products were determined by the Lowry method. — Endosperms separated from seeds at the time of rapid storage protein mobilization (seedling length between 20 and 50 mm) showed high proteinase activities in all three assays. Experiments with different inhibitors suggested that at least four enzymes were involved. One of the enzymes resembled mammalian and microbial pepsin-like acid proteinases: the pH optimum was 3.7 and the enzyme was inhibited by pepstatin.—Th…
Localization and Activity of Naphthylamidases in Germinating Seeds of Scots Pine, Pinus sylvestris
1976
Extracts prepared from endosperms of germinating seeds of Scots pine, Pinus sylvestris L., rapidly hydrolysed the β-naphthylamides of L-phenylalanine and L-leucine optimally at pH 6.5 and that of L-arginine at pH 7.7. Disc electrophoresis followed by activity staining showed that the activities were due to two naphthylamidases (aminopeptidases) with different substrate specificities. Seeds were allowed to germinate at 20°C on agar gel in the dark and the activities on the three substrates were assayed from separated endosperms and seedlings at various stages of germination. The activities in the endosperm of resting seeds were relatively high and they remained unchanged throughout the perio…
The Formation of The Plant Vacuolar System
1999
The plant vacuole is a multifunctional subcellular compartment. In general, the vacuolar system is constituted of a single or few vacuoles. About 80% of the volume of mature plant cells is occupied by vacuoles. These organelles are limited by a single membrane, the tonoplast. According to the cell type and to particular functions, the vacuolar content can vary from a homogeneous consistency to a heterogeneous matrix containing crystalloid structures (Boiler, Wiemken, 1986; Marty et al., 1980). From the biotechnological point of view, the endomembrane system of plants, particularly the ER and vacuoles, can be envisioned as the ultimate environment for stable protein accumulation. Several rep…
A barley (Hordeum vulgare L.) LEA3 protein, HVA1, is abundant in protein storage vacuoles
1996
The HVA1 protein belongs to the LEA3 group, which is expressed during the late stage of seed maturation. It is also induced by exogenous abscisic acid (ABA) and a variety of environmental stresses in germinating barley (Hordeum vulgare L.). In the present work, the potential role of HVA1 was investigated by studying its tissue distribution and subcellular localization in mature and stressed seeds by immuno-microscopic methods. In the mature seed, HVA1 protein was detected in all tissues except the non-living starchy endosperm. During germination the amount of HVA1 protein decreased but did not totally disappear. Incubation with 100 μM ABA, cold treatment or drought stress dramatically incre…
L'accumulation des protéines dans les graines de légumineuses
2017
The agroecological benefits of legumes and the renewed interest in the consumption of vegetable proteins stimulate researches on cognitive and applied aspects of seed biology aiming at optimizing protein composition of legume seeds. This article presents the state of knowledge on the genetic and environmental control of the accumulation of major proteins found in legume seeds, with a view to developing varieties with improved nutritional seed quality. It also shows how high-throughput genomics and post-genomics data, along with translational research aiming at transferring knowledge between model and crop species, can accelerate the identification of genes controlling the accumulation of st…