scholarly journals Improvement in theIn VivoDigestibility of Rice Protein by Alkali Extraction Is Due to Structural Changes in Prolamin/Protein Body-I Particle

2010 ◽  
Vol 74 (3) ◽  
pp. 614-619 ◽  
Author(s):  
Masatoshi KUBOTA ◽  
Yuhi SAITO ◽  
Takehiro MASUMURA ◽  
Takehisa KUMAGAI ◽  
Reiko WATANABE ◽  
...  
Keyword(s):  
Structural Changes ◽  
Protein Body ◽  
Alkali Extraction ◽  
Rice Protein

Structural Aspects of Protein Accumulation in Developing Pea Cotyledons. I. Qualitative and Quantitative Changes in Parenchyma Cell Vacuoles

1979 ◽  
Vol 6 (1) ◽  
pp. 81 ◽  
Author(s):  
S Craig ◽  
DJ Goodchild ◽  
AR Hardham
Keyword(s):  
Cell Volume ◽  
Surface Area ◽  
Structural Changes ◽  
Light And Electron Microscopy ◽  
Parenchyma Cell ◽  
Protein Body ◽  
Average Diameter ◽  
Protein Bodies ◽  
Protein Accumulation ◽  
Parenchyma Cells

Structural changes in pea cotyledons during development were studied using light and electron microscopy. Changes in the vacuolar system and cytoplasm of cotyledon parenchyma cells, during the period of storage protein deposition, are reported. Eight days after flowering, the parenchyma cells each contain one or two large vacuoles that are replaced by progressively smaller vacuoles during the next 10 days of development. Stainable material that can be histochemically identified as protein appears on the inner surface of the vacuole tonoplast 8 days after flowering. These vacuoles become smaller and more frequent during development and the amount of proteinaceous material within each vacuole increases until, at days 16-20 after flowering, they become densely packed with protein and are described as protein bodies. At day 8, the vacuole(s) have an average diameter of 39 �m, an average volume of 41 000 �m� , representing 75 % of the cell volume, and a surface area of 5500 �m�. By day 20, the average protein body diameter has fallen to 1 �m. There are, however, approx. 175 000 such protein bodies per cell, occupying 91 500 �m� or approx. 20 % of the cell volume, and whose total surface area is 550 000 �m�. The surface to volume ratlo of the vacuole/protein bodies Increases 55 times between days 8 and 20. Apart from this increase in surface area available for possible entry of protein, no mechanism for such entry can be suggested from our nlicrographs.

scholarly journals CYTOCHEMICAL AND DEVELOPMENTAL CHANGES IN MICROBODIES (GLYOXYSOMES) AND RELATED ORGANELLES OF CASTOR BEAN ENDOSPERM

1970 ◽  
Vol 46 (3) ◽  
pp. 435-454 ◽  
Author(s):  
Eugene L. Vigil
Keyword(s):  
Cross Section ◽  
Cell Walls ◽  
Matrix Protein ◽  
Structural Changes ◽  
Protein Body ◽  
Seedling Development ◽  
Developmental Changes ◽  
Cytochemical Analysis ◽  
The Matrix ◽  
New Protein

Structural changes in endosperm cells of germinating castor beans were examined and complemented with a cytochemical analysis of staining with diaminobenzidine (DAB). Deposition of oxidized DAB occurred only in microbodies due to the presence of catalase, and in cell walls associated with peroxidase activity. Seedling development paralleled the disappearance of spherosomes (lipid bodies) and matrix of aleurone grains in endosperm cells. 6 to 7 days after germination, a cross-section through the endosperm contained cells in all stages of development and senescence beginning at the seed coat and progressing inward to the cotyledons. Part of this aging process involved vacuole formation by fusion of aleurone grain membranes. This coincided with an increase in microbodies (glyoxsomes), mitochondria, plastids with an elaborate tubular network, and the formation of a new protein body referred to as a dilated cisterna, which is structurally and biochemically distinct from microbodies although both apparently develop from rough endoplasmic reticulum (ER). In vacuolate cells microbodies are the most numerous organelle and are intimately associated with spherosomes and dilated cisternae. This phenomenon is discussed in relation to the biochemical activities of these organelles. Turnover of microbodies involves sequestration into autophagic vacuoles as intact organelles which still retain catalase activity. Crystalloids present in microbodies develop by condensation of matrix protein and are the principal site of catalase formerly in the matrix.

scholarly journals Preparation of Heat-Sensitivity Proteins from Walnut Meal by Sweep Frequency Ultrasound-Assisted Alkali Extraction

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Wenjuan Qu ◽  
Wei Fan ◽  
Yiting Feng ◽  
Yunliang Li ◽  
Haile Ma ◽  
...  
Keyword(s):  
Structural Changes ◽  
Ph Value ◽  
Structural Characteristics ◽  
Duty Ratio ◽  
Heat Sensitivity ◽  
Ultrasonic Frequency ◽  
Sweep Frequency ◽  
Alkali Extraction ◽  
Ultrasonic Time ◽  
Frequency Ultrasound

Sweep frequency ultrasound- (SFU-) assisted alkali extraction was conducted to increase the yield and content of heat-sensitive protein of walnut meal under a relatively mild condition. The physicochemical and structural characteristics of the proteins obtained by SFU-assisted alkali extraction and the conventional alkali extraction were compared. It was found that the optimal parameters for the SFU-assisted extraction were the solid-liquid ratio of 1 : 12, pH value of 9, initial temperature of 25°C, ultrasonic frequency of 28 kHz, sweep frequency amplitude of 1.5 kHz, sweep frequency cycle of 100 ms, duty ratio of 77%, and ultrasonic time of 90 min. Under this condition, a vast improvement in the walnut protein yield (34.9%) and the walnut protein content (9.8%) was observed. Such improvement was due to the structural changes of the sonicated protein; e.g., SFU decreased the intermolecular/intramolecular hydrogen bond force of proteins and, therefore, caused more order secondary structures and more loosen microstructures. This helped to improve the thermoplastic and solubility of the heat-sensitivity protein. Thus, SFU treatment could be an effective auxiliary technology in the alkali extraction of heat-sensitivity walnut protein. It might also be a promising technology for the extraction of heat-sensitivity protein from other agricultural by-products.

scholarly journals Effect of alkali extraction on the digestibility and bioavailability of rice protein

2012 ◽  
Vol 26 (S1) ◽  
Author(s):  
Masatoshi Kubota ◽  
Yuhi Saito ◽  
Takehiro Masumura ◽  
Takehisa Kumagai ◽  
Reiko Watanabe ◽  
...  
Keyword(s):  
Alkali Extraction ◽  
Rice Protein

Fine Structural Changes in the Microvasculature of the Mouse Pinna: Aging and Radiation Injury

1974 ◽  
Vol 32 ◽  
pp. 54-55
Author(s):  
S. Phyllis Steamer ◽  
Rosemarie L. Devine
Keyword(s):  
Structural Changes ◽  
Radiation Treatment ◽  
Arterial Stenosis ◽  
Ultrastructural Changes ◽  
Vascular Effects ◽  
Microvascular Changes ◽  
Surrounding Connective Tissue ◽  
Fission Neutrons ◽  
Total Body

The importance of radiation damage to the skin and its vasculature was recognized by the early radiologists. In more recent studies, vascular effects were shown to involve the endothelium as well as the surrounding connective tissue. Microvascular changes in the mouse pinna were studied in vivo and recorded photographically over a period of 12-18 months. Radiation treatment at 110 days of age was total body exposure to either 240 rad fission neutrons or 855 rad 60Co gamma rays. After in vivo observations in control and irradiated mice, animals were sacrificed for examination of changes in vascular fine structure. Vessels were selected from regions of specific interest that had been identified on photomicrographs. Prominent ultrastructural changes can be attributed to aging as well as to radiation treatment. Of principal concern were determinations of ultrastructural changes associated with venous dilatations, segmental arterial stenosis and tortuosities of both veins and arteries, effects that had been identified on the basis of light microscopic observations. Tortuosities and irregularly dilated vein segments were related to both aging and radiation changes but arterial stenosis was observed only in irradiated animals.

Evaluation of single-electron movies of glutamine synthetase molecules

1983 ◽  
Vol 41 ◽  
pp. 280-281
Author(s):  
W. Kunath ◽  
E. Zeitler ◽  
M. Kessel
Keyword(s):  
Electron Microscope ◽  
Glutamine Synthetase ◽  
Electron Irradiation ◽  
Structural Damage ◽  
Structural Changes ◽  
Single Electron ◽  
Continuous Series ◽  
Digital Recording ◽  
Recording Device ◽  
Low Exposure

The features of digital recording of a continuous series (movie) of singleelectron TV frames are reported. The technique is used to investigate structural changes in negatively stained glutamine synthetase molecules (GS) during electron irradiation and, as an ultimate goal, to look for the molecules' “undamaged” structure, say, after a 1 e/Å2 dose.The TV frame of fig. la shows an image of 5 glutamine synthetase molecules exposed to 1/150 e/Å2. Every single electron is recorded as a unit signal in a 256 ×256 field. The extremely low exposure of a single TV frame as dictated by the single-electron recording device including the electron microscope requires accumulation of 150 TV frames into one frame (fig. lb) thus achieving a reasonable compromise between the conflicting aspects of exposure time per frame of 3 sec. vs. object drift of less than 1 Å, and exposure per frame of 1 e/Å2 vs. rate of structural damage.

Fine Structural Changes in the Adenohypophyses of Rats Following Destruction of the Pituitary Stalk

1977 ◽  
Vol 35 ◽  
pp. 496-497
Author(s):  
K. Kovacs ◽  
E. Horvath ◽  
J. M. Bilbao ◽  
F. A. Laszlo ◽  
I. Domokos
Keyword(s):  
Structural Changes ◽  
Tissue Injury ◽  
Anterior Lobe ◽  
Uranyl Acetate ◽  
Male Rats ◽  
Pituitary Stalk ◽  
Sequence Of Events ◽  
Pituitary Glands ◽  
Electrolytic Lesions ◽  
Ultrathin Sections

Electrolytic lesions of the pituitary stalk in rats interrupt adenohypophysial blood flow and result in massive infarction of the anterior lobe. In order to obtain a deeper insight into the morphogenesis of tissue injury and to reveal the sequence of events, a fine structural investigation was undertaken on adenohypophyses of rats at various intervals following destruction of the pituitary stalk.The pituitary stalk was destroyed electrolytically, with a Horsley-Clarke apparatus on 27 male rats of the R-Amsterdam strain, weighing 180-200 g. Thirty minutes, 1,2,4,6 and 24 hours after surgery the animals were perfused with a glutaraldehyde-formalin solution. The skulls were then opened and the pituitary glands removed. The anterior lobes were fixed in glutaraldehyde-formalin solution, postfixed in osmium tetroxide and embedded in Durcupan. Ultrathin sections were stained with uranyl acetate and lead citrate and investigated with a Philips 300 electron microscope.

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