A proposed pathway of plasma glycoprotein synthesis

1975 ◽  
Vol 6 (1) ◽  
pp. 3-14 ◽  
Author(s):  
Janos Molnar
Keyword(s):  
Glycoprotein Synthesis ◽  
Plasma Glycoprotein

Impairment of plasma glycoprotein synthesis in choline deficiency compared with effects of carbon tetrachloride intoxication

1968 ◽  
Vol 46 (3) ◽  
pp. 499-505 ◽  
Author(s):  
Sailen Mookerjea
Keyword(s):  
Carbon Tetrachloride ◽  
Plasma Proteins ◽  
Specific Radioactivity ◽  
Starch Gel Electrophoresis ◽  
Choline Deficiency ◽  
Deficient Diet ◽  
Glycoprotein Synthesis ◽  
Carbon Tetrachloride Intoxication ◽  
Starch Gel ◽  
Plasma Glycoprotein

The incorporation of glucosamine-1-14C into plasma proteins is impaired in rats within 2 days when they are fed a choline-deficient diet. Separation of plasma proteins by starch-gel electrophoresis, and autoradiography of the dried gels, showed four labelled areas (glycoproteins). In choline deficiency there was visual evidence of depletion of radioactivity in the fast α-globulin area, a finding confirmed by the specific radioactivity of proteins eluted from electrophoretic zones of the starch gel. Within 4 h after ingestion of carbon tetrachloride, the synthesis of plasma glycoprotein was reduced by 90% and labelling of all four glycoprotein areas on dried starch gel autoradiograms virtually ceased. The results suggest that the defect in glycoprotein synthesis in carbon tetrachloride intoxication is nonspecific, whereas in choline deficiency the impairment is specific and localized in the fast α-globulin fraction. The results suggest a limiting role of a glycoprotein in the pathway of plasma lipoprotein synthesis.

The Use of Nucleotide-Sugar: Glycoprotein Glycosyltransferases to Assess Golgi Apparatus Function in Morris Hepatomas

1971 ◽  
Vol 49 (1) ◽  
pp. 61-70 ◽  
Author(s):  
R. L. Hudgin ◽  
R. K. Murray ◽  
L. Pinteric ◽  
H. P. Morris ◽  
H. Schachter
Keyword(s):  
Golgi Apparatus ◽  
Rat Liver ◽  
Nucleotide Sugar ◽  
Glycoprotein Synthesis ◽  
Enzymatic Assays ◽  
Tumor Bearing ◽  
Normal Rat ◽  
Liver Homogenates ◽  
Plasma Glycoprotein ◽  
Slow Growing

Enzymatic assays for CMP-sialic acid: glycoprotein sialyltransferase and UDP-N-acetylglucosamine: glycoprotein N-acetylglucosaminyltransferase were performed on crude homogenates of three Morris hepatomas (7777, 7800, and 5123D), and on liver homogenates from the host animals and normal Buffalo strain rats. It was found that sialyltransferase activities were greatly decreased in the most rapidly growing tumor (hepatoma 7777) and were decreased to a lesser extent in the more slowly growing hepatoma 7800; enzyme activities in hepatoma 5123D, another relatively slow growing tumor, were not significantly different from control values. Sialyltransferase activities were significantly elevated in the livers of all the tumor-bearing animals and were especially high in the livers of animals carrying hepatoma 7777; these elevations may be related to increased plasma glycoprotein synthesis by liver secondary to the inflammatory stimulus generated by the tumors. In contrast to the sialyltransferase analyses, N-acetylglucosaminyltransferase activities in tumor homogenates were very similar to control values for all three hepatomas. When the data are expressed as ratios of sialyltransferase activity to N-acetylglucosaminyltransferase activity, two of the three tumors show highly significant decreases of this ratio compared to either control or host livers. Since these glycosyltransferases have previously been shown to be located in the Golgi apparatus of normal rat liver where they function in the biosynthesis of glycoproteins, the above results have been interpreted to indicate a shift in the function of the Golgi apparatus in certain Morris hepatomas as compared to normal livers. Finally, glycosyltransferase assays and electron microscopy have been used to demonstrate the feasibility of preparing Golgi-enriched fractions from all three hepatomas by methods previously applied to normal rat liver.

PLASMA GLYCOPROTEIN SYNTHESIS IN ALLOXAN-DIABETIC RATS

1971 ◽  
Vol 50 (2) ◽  
pp. 355-356 ◽  
Author(s):  
S. V. CAPREOL ◽  
L. E. SUTHERLAND ◽  
D. A. HANIMYAN
Keyword(s):  
Diabetic Rats ◽  
Glycoprotein Synthesis ◽  
Plasma Glycoprotein

scholarly journals Improving cell-free glycoprotein synthesis by characterizing and enriching native membrane vesicles

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jasmine M. Hershewe ◽  
Katherine F. Warfel ◽  
Shaelyn M. Iyer ◽  
Justin A. Peruzzi ◽  
Claretta J. Sullivan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Synthetic Biology ◽  
Membrane Protein ◽  
Membrane Vesicles ◽  
Processing Methods ◽  
Glycoprotein Synthesis ◽  
On Demand ◽  
Free Gene ◽  
Membrane Bound

AbstractCell-free gene expression (CFE) systems from crude cellular extracts have attracted much attention for biomanufacturing and synthetic biology. However, activating membrane-dependent functionality of cell-derived vesicles in bacterial CFE systems has been limited. Here, we address this limitation by characterizing native membrane vesicles in Escherichia coli-based CFE extracts and describing methods to enrich vesicles with heterologous, membrane-bound machinery. As a model, we focus on bacterial glycoengineering. We first use multiple, orthogonal techniques to characterize vesicles and show how extract processing methods can be used to increase concentrations of membrane vesicles in CFE systems. Then, we show that extracts enriched in vesicle number also display enhanced concentrations of heterologous membrane protein cargo. Finally, we apply our methods to enrich membrane-bound oligosaccharyltransferases and lipid-linked oligosaccharides for improving cell-free N-linked and O-linked glycoprotein synthesis. We anticipate that these methods will facilitate on-demand glycoprotein production and enable new CFE systems with membrane-associated activities.

scholarly journals Control of Glycoprotein Synthesis

1989 ◽  
Vol 264 (19) ◽  
pp. 11211-11221
Author(s):  
I Brockhausen ◽  
E Hull ◽  
O Hindsgaul ◽  
H Schachter ◽  
R N Shah ◽  
...  
Keyword(s):  
Glycoprotein Synthesis
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