Protein composition and protein synthesis in the surface membranes of Schistosoma mansoni

Parasitology ◽  
1972 ◽  
Vol 65 (1) ◽  
pp. 55-69 ◽  
Author(s):  
J. R. Kusel
Keyword(s):  
Protein Synthesis ◽  
Calcium Chloride ◽  
Unit Area ◽  
Surface Membrane ◽  
Biological Significance ◽  
Protein Composition ◽  
Major Protein ◽  
Freezing And Thawing ◽  
Protein Components ◽  
Protein Incorporation

Saponin treatment of cercariae and schistosomula alters the surface membrane so that it may be sheared from the organism and isolated as fragments by centrifugation. Saponin-calcium chloride treatment or freezing and thawing of adult worms removes the surface membrane, which can be washed from the bodies and collected by centrifugation. The small quantities of material available necessitated the development of a sensitive technique for detecting the proteins in the membranes. The surface membranes were radioiodinated after butan-1-ol extraction and electrophoresed in polyacrylamide gel. Adult surfaces prepared by the saponin-calcium chloride and by the freezing and thawing technique had identical protein components, detected as gel-cut profiles or in autoradiographs. The quantity of a rapidly migrating PAS-positive amido black negative component was greater in the surfaces prepared by saponincalcium chloride than in the frozen and thawed surfaces. This component contains lipid, some of which may be glycolipid. It was largely absent from the surface membranes of cercariae and schistosomula. Cercarial surface membranes contained a major protein component which was absent from the surface membranes of schistosomula. Otherwise the surface membranes of the cercariae were identical to those of the schistosomula in their protein components. The rate of incorporation of freshly synthesized protein per unit area of surface membrane of schistosomula was very low in the first 5 days in culture, after which there was a very rapid increase to a maximum rate on the 15th day. After this time, the rate of protein synthesis decreased to a low level at 26 days. In these studies the activity per unit area was measured and this would not be expected to vary greatly during growth. The biological significance of the observed variation in protein incorporation into the membrane is unclear.

Stage-specific patterns of collagen gene expression during development of Caenorhabditis elegans

1985 ◽  
Vol 5 (2) ◽  
pp. 363-372
Author(s):  
G N Cox ◽  
D Hirsh
Keyword(s):  
Caenorhabditis Elegans ◽  
Protein Composition ◽  
Large Family ◽  
Major Protein ◽  
Mrna Levels ◽  
Mrna Accumulation ◽  
C Elegans ◽  
Collagen Protein ◽  
Protein Components ◽  
Collagen Genes

Collagens are the major protein components of the Caenorhabditis elegans cuticle and are encoded by a large family of 40 to 150 closely related but nonidentical genes. We have determined temporal patterns of mRNA accumulation for a large number of collagen genes by screening recombinant phages and plasmids containing cloned collagen genes under high stringency conditions with 32P-labeled cDNA preparations specific for eggs or three postembryonic molts. We find that collagen mRNA levels are regulated both temporally and quantitatively during C. elegans development. Most genes studied exhibit one of four patterns of mRNA accumulation which correlate with changes in cuticle morphology and collagen protein composition during development. Our results suggest that, in general, there is a progressive activation of new collagen genes during normal development.

scholarly journals Venomics and Cellular Toxicity of Thai Pit Vipers (Trimeresurus macrops and T. hageni)

Toxins ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 54 ◽  
Author(s):  
Supeecha Kumkate ◽  
Lawan Chanhome ◽  
Tipparat Thiangtrongjit ◽  
Jureeporn Noiphrom ◽  
Panithi Laoungboa ◽  
...  
Keyword(s):  
Snake Venom ◽  
Protein Composition ◽  
Treatment Method ◽  
Cross Reactivity ◽  
Major Protein ◽  
Dependent Manner ◽  
Crude Venom ◽  
Monocytic Cells ◽  
Protein Components ◽  
Species Specific

The two venomous pit vipers, Trimeresurus macrops and T. hageni, are distributed throughout Thailand, although their abundance varies among different areas. No species-specific antivenom is available for their bite victims, and the only recorded treatment method is a horse antivenom raised against T. albolabris crude venom. To facilitate assessment of the cross-reactivity of heterologous antivenoms, protein profiles of T. macrops and T. hageni venoms were explored using mass-spectrometry-based proteomics. The results show that 185 and 216 proteins were identified from T. macrops and T. hageni venoms, respectively. Two major protein components in T. macrops and T. hageni venoms were snake venom serine protease and metalloproteinase. The toxicity of the venoms on human monocytes and skin fibroblasts was analyzed, and both showed a greater cytotoxic effect on fibroblasts than monocytic cells, with toxicity occurring in a dose-dependent rather than a time-dependent manner. Exploring the protein composition of snake venom leads to a better understanding of the envenoming of prey. Moreover, knowledge of pit viper venomics facilitates the selection of the optimum heterologous antivenoms for treating bite victims.

scholarly journals Stage-specific patterns of collagen gene expression during development of Caenorhabditis elegans.

1985 ◽  
Vol 5 (2) ◽  
pp. 363-372 ◽  
Author(s):  
G N Cox ◽  
D Hirsh
Keyword(s):  
Caenorhabditis Elegans ◽  
Protein Composition ◽  
Large Family ◽  
Major Protein ◽  
Mrna Levels ◽  
Mrna Accumulation ◽  
C Elegans ◽  
Collagen Protein ◽  
Protein Components ◽  
Collagen Genes

Collagens are the major protein components of the Caenorhabditis elegans cuticle and are encoded by a large family of 40 to 150 closely related but nonidentical genes. We have determined temporal patterns of mRNA accumulation for a large number of collagen genes by screening recombinant phages and plasmids containing cloned collagen genes under high stringency conditions with 32P-labeled cDNA preparations specific for eggs or three postembryonic molts. We find that collagen mRNA levels are regulated both temporally and quantitatively during C. elegans development. Most genes studied exhibit one of four patterns of mRNA accumulation which correlate with changes in cuticle morphology and collagen protein composition during development. Our results suggest that, in general, there is a progressive activation of new collagen genes during normal development.

Characterization of excretory–secretory products from protoscoleces of Echinococcus granulosus and evaluation of their potential for immunodiagnosis of human cystic echinococcosis

Parasitology ◽  
2004 ◽  
Vol 129 (3) ◽  
pp. 371-378 ◽  
Author(s):  
D. CARMENA ◽  
J. MARTÍNEZ ◽  
A. BENITO ◽  
J. A. GUISANTES
Keyword(s):  
Echinococcus Granulosus ◽  
Cystic Echinococcosis ◽  
Secretory Protein ◽  
Major Protein ◽  
Healthy Donors ◽  
Secretory Products ◽  
Protein Components ◽  
Human Cystic Echinococcosis

This study describes, for the first time, the characterization of excretory–secretory antigens (ES-Ag) from Echinococcus granulosus protoscoleces, evaluating their usefulness in the immunodiagnosis of human cystic echinococcosis. ES-Ag were obtained from the first 50 h maintenance of protoscoleces in vitro. This preparation contained over 20 major protein components which could be distinguished by 1-dimensional SDS–PAGE with apparent masses between 9 and 300 kDa. The culture of of protoscoleces from liver produced a greater variety of excretory–secretory protein components than those from lung. Determination of enzymatic activities of secreted proteins revealed the presence of phosphatases, lipases and glucosidases, but no proteases. These findings were compared to those obtained from somatic extracts of protoscoleces and hydatid cyst fluid products. Immunochemical characterization was performed by immunoblotting with sera from individuals infected by cystic echinococcosis (n=15), non-hydatidic parasitoses (n=19), various liver diseases (n=24), lung neoplasia (n=16), and healthy donors (n=18). Antigens with apparent masses of 89, 74, 47/50, 32, and 20 kDa showed specificity for immunodiagnosis of human hydatidosis. The 89 and 74 kDa components corresponded to antigens not yet described in E. granulosus, whereas proteins of 41–43 kDa and 91–95 kDa were recognized by the majority of the non-hydatid sera studied.

scholarly journals Diphtheria toxin entry into cells is facilitated by low pH.

1980 ◽  
Vol 87 (3) ◽  
pp. 828-832 ◽  
Author(s):  
K Sandvig ◽  
S Olsnes
Keyword(s):  
Protein Synthesis ◽  
Toxic Effect ◽  
Diphtheria Toxin ◽  
Surface Membrane ◽  
Low Ph ◽  
Toxin A ◽  
Neutral Ph ◽  
Diphtheria Toxin A ◽  
Adsorptive Endocytosis

At neutral pH, NH4Cl and chloroquine protected cells against diphtheria toxin. A brief exposure of the cells to low pH (4.5-5.5) at 37 degrees completely abolished this protection. When, to cells preincubated with diphtheria toxin and NH4Cl, neutralizing amounts of anti-diphtheria toxin were added before the pH was lowered, the toxic effect was considerably reduced, but it was not completely abolished. A much stronger toxic effect was seen when antibodies were added immediately after incubation at low pH. Upon a short incubation with diphtheria toxin at low pH, the rate of protein synthesis in the cells decreased much faster than when the normal pH was maintained. The data suggest that, at low pH, diphtheria toxin (or its A fragment) penetrates directly through the surface membrane of the cell. The possibility is discussed that, when the medium has a neutral pH, the entry of diphtheria toxin involves adsorptive endocytosis and reduction of the pH in the vesicles possibly by fusion with lysosomes. Low pH did not facilitate the entry of the closely related toxins abrin, ricin, and modeccin.

scholarly journals Simulated Breathing: Application of Molecular Dynamics Simulations to Pulmonary Lung Surfactant

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1259
Author(s):  
Maksymilian Dziura ◽  
Basel Mansour ◽  
Mitchell DiPasquale ◽  
P. Charukeshi Chandrasekera ◽  
James W. Gauld ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Pulmonary Surfactant ◽  
Lung Surfactant ◽  
Protein Composition ◽  
Md Simulations ◽  
Building Blocks ◽  
Future Research ◽  
Total Composition ◽  
Protein Components ◽  
Dynamics Simulations

In this review, we delve into the topic of the pulmonary surfactant (PS) system, which is present in the respiratory system. The total composition of the PS has been presented and explored, from the types of cells involved in its synthesis and secretion, down to the specific building blocks used, such as the various lipid and protein components. The lipid and protein composition varies across species and between individuals, but ultimately produces a PS monolayer with the same role. As such, the composition has been investigated for the ways in which it imposes function and confers peculiar biophysical characteristics to the system as a whole. Moreover, a couple of theories/models that are associated with the functions of PS have been addressed. Finally, molecular dynamic (MD) simulations of pulmonary surfactant have been emphasized to not only showcase various group’s findings, but also to demonstrate the validity and importance that MD simulations can have in future research exploring the PS monolayer system.

Protein composition of nuclear matrix preparations from HeLa cells: an immunochemical approach

1986 ◽  
Vol 80 (1) ◽  
pp. 103-122
Author(s):  
R. Verheijen ◽  
H. Kuijpers ◽  
P. Vooijs ◽  
W. van Venrooij ◽  
F. Ramaekers
Keyword(s):  
Nuclear Matrix ◽  
Connective Tissue Diseases ◽  
Protein Composition ◽  
Cytoskeletal Proteins ◽  
Two Dimensional ◽  
Two Dimensional Gel Electrophoresis ◽  
Core Proteins ◽  
Nuclear Rna ◽  
Hela S3 ◽  
Protein Components

Procedures for the isolation of HeLa S3 nuclear matrices were re-examined with special emphasis on the use of various nucleases and detergents as well as on the ionic strength of the final salt extraction. The protein composition of the resulting nuclear matrix preparations was analysed by one- and two-dimensional gel electrophoresis and found to be extremely reproducible. By means of co-electrophoresis several typical cytoskeletal proteins (actin, vimentin and cytokeratins) and heterogeneous nuclear RNA (hnRNA)-associated core proteins (hnRNP) were shown to be present in such nuclear matrix preparations. The nature of some other protein components was elucidated using two-dimensional immunoblotting and immunofluorescence. For this purpose mouse monoclonal antibodies to cytoskeletal components (vimentin, cytokeratins), small nuclear RNP (70 X 10(3) Mr protein of U1-RNP), hnRNP (C1/C2) and the pore-complex lamina (lamins A, B and C) were used next to human autoimmune sera obtained from patients with connective tissue diseases and directed against the residual nucleoli and the internal fibrillar mass. These antibodies enabled us to identify a number of proteins present specifically in the nuclear matrix and to show that part of the cytoskeletal proteins are still present in the isolated structures.

Use of an in Vitro Protein Synthesizing System to Test the Mode of Action of Chloracetamides

Weed Science ◽  
1980 ◽  
Vol 28 (3) ◽  
pp. 334-340 ◽  
Author(s):  
Luanne M. Deal ◽  
J. T. Reeves ◽  
B. A. Larkins ◽  
F. D. Hess
Keyword(s):  
Protein Synthesis ◽  
Sand Culture ◽  
Leucine Incorporation ◽  
Insoluble Protein ◽  
In Vitro System ◽  
A Cell ◽  
Protein Incorporation ◽  
Vitro Protein

The effects of chloracetamides on protein synthesis were studied both in vivo and in vitro. Four chloracetamide herbicides, alachlor [2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide], metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide], CDAA (N–N-diallyl-2-chloroacetamide), and propachlor (2-chloro-N-isopropylacetanilide) were tested for inhibition of [3H]-leucine incorporation into protein. Incorporation of3H-leucine into trichloroacetic acid (TCA)-insoluble protein was inhibited in oat (Avena sativaL. ‘Victory’) seedlings grown in sand culture and treated 12 h at 1 × 10−4M with these chloracetamides. The herbicides were also tested in a cell-free protein synthesizing system containing polyribosomes purified from oat root cytoplasm. These herbicides had no effect on the rates of polypeptide elongation nor on the synthesis of specific polypeptides when herbicides (1 × 10−4M) were added directly to the system. Polypeptide formation was inhibited 89% when 1 × 10−4M cycloheximide was added during translation. Cytoplasmic polyribosomes were isolated from oat roots treated 12 h with 1 × 10−4M herbicide. Translation rates and products were not altered when these polyribosomes were added to the in vitro system. Protein synthesis is inhibited when tested in an in vivo system; however, the inhibition does not occur during the translation of mRNA into protein.

scholarly journals Mitochondrial volume fraction and translation duration impact mitochondrial mRNA localization and protein synthesis

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Tatsuhisa Tsuboi ◽  
Matheus P Viana ◽  
Fan Xu ◽  
Jingwen Yu ◽  
Raghav Chanchani ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Energy Demand ◽  
Volume Fraction ◽  
Protein Composition ◽  
Mrna Localization ◽  
Geometric Constraints ◽  
Specific Gene ◽  
Translation Elongation ◽  
Mitochondrial Volume ◽  
Necessary And Sufficient

Mitochondria are dynamic organelles that must precisely control their protein composition according to cellular energy demand. Although nuclear-encoded mRNAs can be localized to the mitochondrial surface, the importance of this localization is unclear. As yeast switch to respiratory metabolism, there is an increase in the fraction of the cytoplasm that is mitochondrial. Our data point to this change in mitochondrial volume fraction increasing the localization of certain nuclear-encoded mRNAs to the surface of the mitochondria. We show that mitochondrial mRNA localization is necessary and sufficient to increase protein production to levels required during respiratory growth. Furthermore, we find that ribosome stalling impacts mRNA sensitivity to mitochondrial volume fraction and counterintuitively leads to enhanced protein synthesis by increasing mRNA localization to mitochondria. This points to a mechanism by which cells are able to use translation elongation and the geometric constraints of the cell to fine-tune organelle-specific gene expression through mRNA localization.

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