Isoelectric forms of clusterin isolated from ram rete testis fluid and from secretions of primary cultures of ram and rat Sertoli-cell-enriched preparations

1984 ◽  
Vol 62 (6) ◽  
pp. 456-461 ◽  
Author(s):  
O. W. Blaschuk ◽  
I. B. Fritz

Clusterin, a cell aggregating factor isolated from ram rete testis fluid (RTF), is shown to contain 14.7% hexoses, 13.6% glucosamine, and 7.9% sialic acid. The isoelectric point (pI) of the predominant electrophoretic form of clusterin from ram RTF is 3.7. After treatment with neuraminidase, the pI values become more basic, with the majority of the material being eluted from a chromatofocusing column at pH values between 4.9 and 5.1. Intact clusterin binds quantitatively to wheat germ agglutinin – Sepharose 6 MB, but after treatment with neuraminidase only 49% specifically binds. Clusterin isolated from proteins secreted by primary cultures of ram Sertoli-cell-enriched preparations was shown to have properties similar to those of intact clusterin isolated from ram RTF. In contrast, clusterin isolated from proteins secreted by primary cultures of rat Sertoli- or granulosa-cell-enriched preparations has isoelectric forms which more closely resemble those of neuraminidase-treated ram clusterin.


2021 ◽  
Vol 38 (3) ◽  
pp. 266-271
Author(s):  
Yosun MATER ◽  
Günnur DEMİRCAN

The importance of early cancer diagnosis has led to development of many different diagnostic methods. In this context, the studies investigating the presence and amount of sugar residues to use as indicators in the identification of cancer cell type have become prominent. In the present study, sialic acids found on the membrane surfaces of ER (+) MCF-7 and ER (-) MDA-MB-231 breast cancer cell lines were labeled using three-dimensional (3D) cell culture (Spheroid) model as the closest method to the patient sample, thus its natural environment, among the cell culture methods. These sugar units that play a role in regulation of important immune characteristics such as recognition, binding and metastasis were made visualizable by applying fluorescent-labeled lectins such as FITC-(Wheat Germ Agglutinin) specifically binding to sialic acid units (GlcNAc, Neu5Ac) including particularly ß-GlcNAc and FITC-(Maackia Amurensis-Lectin-1) specifically binding to Galß4GlcNAc type sialic acids. These glycan units were specifically labeled with FITC-(Maackia Amurensis-Lectin-1) and FITC- (Wheat Germ Agglutinin) and radiation intensities were analyzed relatively. The two different breast cancer cell cultures were compared with respect to change in the amounts of sialic acid residues containing α-2,3- and α-2,6 bonds using fluorescent-labeled lectins. In the present study, we have performed a precise, accurate and rapid determination of the sugar content in the different breast cancer cell surface lines by means of fluorescent-labeled lectins and carried out a relative comparison between the micrographs.



Biochemistry ◽  
1979 ◽  
Vol 18 (24) ◽  
pp. 5505-5511 ◽  
Author(s):  
Barry P. Peters ◽  
Shigeyuki Ebisu ◽  
Irwin J. Goldstein ◽  
Michael Flashner


2018 ◽  
Vol 6 (36) ◽  
pp. 5729-5737 ◽  
Author(s):  
Aekta Upadhyay ◽  
Ravinder Kandi ◽  
Chebrolu Pulla Rao

The magnetic iron oxide nanoparticles were coated with a fluorescent torch and were further tagged with wheat germ agglutinin so as to direct the resulting nanocomplex selectively towards breast cancer cells in order to deliver the drug.



1980 ◽  
Vol 85 (1) ◽  
pp. 60-69 ◽  
Author(s):  
P Stanley ◽  
T Sudo ◽  
J P Carver

Two Chinese hamster ovary (CHO) cell mutants selected for resistance to wheat germ agglutinin (WGA) have been shown to exhibit defective sialylation of membrane glycoproteins and a membrane glycolipid, GM3. The mutants (termed WgaRII and WgaRIII) have been previously shown to belong to different genetic complementation groups and to exhibit different WGA-binding abilities. These mutants and a WGA-resistant CHO cell mutant termed WgaRI (which also possesses a surface sialylation defect arising from a deficient N-acetylglucosaminyltransferase activity), have enabled us to investigate the role of sialic acid in WGA binding at the cell surface. Scatchard plots of the binding of 125I-WGA (1 ng/ml to 1 mg/ml) to parental and WgaR CHO cells before and after a brief treatment with neuraminidase provide evidence for several different groups of sialic acid residues at the CHO cell surface which may be distinquished by their differential involvement in WGA binding to CHO cells.



1982 ◽  
Vol 92 (2) ◽  
pp. 277-282 ◽  
Author(s):  
J Finne ◽  
M M Burger ◽  
J P Prieels

In the search for the biochemical basis of the control of glycosylation of cell surface carbohydrates, revertant clones were isolated from previously characterized wheat germ agglutinin-resistant clones of B16 mouse melanoma cells by selection for resistance to Lotus tetragonolobus lectin or to ricin. Comparison of the wheat germ agglutinin-resistant clones with the parent and revertant clones indicated that this phenotype was correlated with an increased sensitivity to the Lotus lectin, a 60- to 70-fold increase in alpha 1 leads to 3 fucosyltransferase activity and a decreased sialic acid content of the N-glycosidic chains of glycoproteins. The results suggest a novel type of control mechanism for lectin resistance, an increase in a glycosyltransferase activity. The presence of alpha 1 leads to 3 bound fucose on N-acetylglucosamine residues would interfere with the addition of sialic acid by alpha 2 leads to 3 linkages to galactose residues in the carbohydrate units, and this change could explain the resistance to wheat germ agglutinin and the increased sensitivity to the Lotus lectin. A change in a regulatory gene for the fucosyltransferase as a possible primary cause for the changed phenotype is discussed.



1994 ◽  
Vol 107 (3) ◽  
pp. 529-537 ◽  
Author(s):  
P.A. Johnston ◽  
A. Stieber ◽  
N.K. Gonatas

We have reported that MG160, an intrinsic membrane sialoglycoprotein of the Golgi apparatus (GA), resides in the medial cisternae of the organelle (Gonatas et al. (1989) J. Biol. Chem. 264, 646–653). In order to resolve the question whether MG160 acquires sialic acid residues in the trans cisternae or trans-Golgi network (TGN) prior to its retrograde transport, we have examined the effects of brefeldin A (BFA) on the post-translational processing of MG160, and the distribution of internalized wheat germ agglutinin covalently linked with HRP (WGA-HRP), which labels the TGN (Gonatas et al. (1977) J. Cell Biol. 73, 1–13). In BFA-treated PC12 cells, MG160 acquires resistance to endo H, but fails to be sialylated. This effect occurs in parallel with the redistribution of MG160 into an ER compartment dispersed throughout the cytoplasm including the nuclear envelope, and the collapse of the WGA-HRP-labelled TGN into vesicles and tubules surrounding the centriole. These results suggest that MG160 is not sialylated in BFA-treated cells because it is sequestered from the sialyltransferase enzyme(s), presumably located in the TGN, and provide evidence supporting the hypothesis for a retrograde transport pathway that recycles resident GA proteins, including MG160, between the Golgi cisternae and the TGN. To examine further the above hypothesis we studied cells treated with BFA and then allowed to recover from the effect of the drug for various lengths of time. After 15 minutes of recovery, cisternae of the Golgi apparatus, typically found in the pericentriolar region, are labeled by both MG160 and WGA-HRP.(ABSTRACT TRUNCATED AT 250 WORDS)



1997 ◽  
Vol 75 (11) ◽  
pp. 1472-1482 ◽  
Author(s):  
Serge J. Meunier ◽  
Quigquan Wu ◽  
Sho-Nong Wang ◽  
René Roy

Hyperbranched glycodendrimers containing sialic acid residues were synthesized in order to further understand the multivalency effect and its role in carbohydrate–protein interactions. Gallic acid 7 as trivalent core and oligoethylene glycol derivatives as hydrophilic spacers were used to scaffold the dendritic backbones. α-Thiosialoside 16 was conjugated onto N-chloroacetylated dendritic precursors 13,14, and 26 by nucleophilic substitution to afford trivalent 17,18, and nonavalent 27 sialodendrimers. Complete sugar deprotection furnished water-soluble α-thiosialodendrimers 21,22, and 29, which were used in protein-binding studies. Turbidimetric analysis confirmed the strong potential of sialodendrimers 29 having nine readily accessible sialic acid residues to bind, cross-link, and precipitate two different lectins. Preliminary results indicated that nonavalent α-sialodendrimer 29 had a greater affinity towards dimeric wheat germ agglutinin (WGA) and the lectin from the slug Limaxflavus (LFA) than the corresponding trivalent glycodendrimers 21 and 22. Keywords: carbohydrate, dendrimer, sialic acid, gallic acid, lectin, wheat germ agglutinin, Limaxflavus.



Tetrahedron ◽  
2004 ◽  
Vol 60 (3) ◽  
pp. 771-780 ◽  
Author(s):  
Roger J. Lins ◽  
Sabine L. Flitsch ◽  
Nicholas J. Turner ◽  
Ed Irving ◽  
Stuart A. Brown


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