scholarly journals Wheat-germ-agglutinin and Ricinus communis-agglutinin-binding sites of BHK cells compared with each other and with 140 kDa fibronectin receptors

1988 ◽  
Vol 251 (1) ◽  
pp. 269-277 ◽  
Author(s):  
T L Tuan ◽  
F Grinnell

We compared the wheat-germ agglutinin (WGA) and Ricinus communis agglutinin (RCA) binding sites of baby-hamster kidney (BHK) cells. There were 1.01 × 10(8) WGA-binding sites per cell (Kd = 0.027 nM) and 6 × 10(6) RCA-binding sites per cell (Kd = 0.014 nM). Binding of WGA or RCA to BHK cells resulted in more than 75% of the cell-surface binding sites becoming associated with the cytoskeleton (i.e. resistant to extraction with detergent), although no more than 10% of these sites were associated with the cytoskeleton before addition of the lectins. After binding of WGA to the cells, the cell surface was cross-linked so extensively that it remained intact even after detergent extraction of the treated cells, and could be observed by electron microscopy. A similar cross-linking effect did not occur after binding of RCA to cells, which may be because there were so many more binding sites for WGA than for RCA. The composition of WGA- and RCA-binding molecules was analysed by lectin affinity chromatography of metabolically radiolabelled BHK cells. We found that in the WGA-binding-molecule preparations there were eight major polypeptides, ranging in molecular mass from 93 to 340 kDa, and that the RCA-binding molecules were a subpopulation of the WGA-binding molecules. A polyclonal antibody against the 140 kDa fibronectin (FN) receptors of Chinese-hamster ovary (CHO) cells immunoblotted a 145 kDa polypeptide component in both WGA- and RCA-binding-molecule preparations. The results indicated that the 145 kDa component was present in at least two FN-receptor complexes that differed in glycosylation, only one of which was able to bind to RCA affinity columns. The oligomeric nature of the FN-receptor complex, which contained three polypeptides with molecular masses of 120-145 kDa, was demonstrated by using anti-(CHO-cell FN receptor) antibodies to immunoprecipitate extracts prepared from radioiodinated BHK cells.

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.


1991 ◽  
Vol 81 (3) ◽  
pp. 393-399 ◽  
Author(s):  
Masayuki Hosoi ◽  
Shokei Kim ◽  
Kenjiro Yamamoto

1. In this study, the carbohydrate structure of pure human renin was examined by using various lectins. 2. Pure renin could be separated into three forms by concanavalin A chromatography, a concanavalin A-unbound form, a loosely bound form and a tightly bound form, termed renins A, B and C, respectively. Renins A, B and C accounted for 3, 13 and 84%, respectively, of the purified renin. These forms were all present in individual human plasma and the relative proportions in plasma were 27 ± 3, 33 ± 4 and 39 ± 5% (means ± sem) for renins A, B and C, respectively (n = 5). 3. Each form, electroblotted on to the nitrocellulose sheet after gel electrophoresis, was incubated with five peroxidase-labelled lectins, lentil lectin, erythroagglutinating phytohaemagglutinin, wheat-germ agglutinin, Ricinus communis agglutinin and peanut agglutinin. The protein was stained with 4-chloro-l-naphthol. 4. The staining pattern obtained with these lectins was significantly different among the three forms of human renin, confirming that they have different carbohydrate structures. Furthermore, the positive staining of human renin with erythroagglutinating phytohaemagglutinin, wheat-germ agglutinin and Ricinus communis agglutinin was in contrast with the lack of binding of rat renin to these lectins. 5. These results indicate the renal secretion of differently glycosylated multiple forms of human renin. The carbohydrate structure of human renin appears to differ from that of rat renin.


Author(s):  
Anni Nurliani ◽  
Teguh Budi Pitojo ◽  
Dwi Liliek Kusindarta

Penelitian ini bertujuan mengkaji efisiensi pencernaan kerbau rawa dengan mengidentifikasi jenis dan distribusi glikokonjugat  pada daerah abomasum kerbau rawa. Enam ekor kerbau rawa jantan >2,5 tahun dan berat badan 300-400 kg digunakan dalam penelitian ini. Sampel diperoleh dari rumah potong hewan (RPH) Kabupaten Banjar, Kalimantan Selatan. Setiap bagian abomasum meliputi kardiak, fundus, dan pilorus diambil untuk pengamatan mikroskopis dengan pewarnaan hematoksilin-eosin (HE) dan alcian blue-periodic acid schiff (AB-PAS). Residu gula glikokonjugat pada abomasum dideteksi dengan pewarnaan histokimia lektin dengan menggunakan wheat germ agglutinin (WGA), ricinus communis agglutinin (RCA), concanavalin agglutinin (Con A), ulex europaeus agglutinin (UEA), dan soybean agglutinin (SBA). Hasil penelitian menunjukkan bahwa daerah kardiak mengandung glikokonjugat D manosa/D glukosa, D galaktosa, dan N asetilglukosamin.  Daerah fundus mengandung D manosa/D glukosa, D galaktosa, L fukosa, N asetilglukosamin, dan N asetilgalaktosamin. Daerah pilorus mengandung glikokonjugat L fukosa dan N asetilglukosamin. Pola reaktivitas daerah kardiak, fundus, dan pilorus kerbau rawa terhadap pewarnaan histokimia lektin memiliki pola yang berbeda dengan ruminansia lain. Jenis glikokonjugat yang dimiliki oleh kerbau rawa tersebut diduga berkaitan dengan fungsi peningkatan kemampuan efisiensi pencernaan kerbau rawa. Setiap bagian abomasum kerbau rawa memiliki jenis glikokonjugat yang spesifik dengan pola distribusi khas sesuai dengan fungsinya.


1982 ◽  
Vol 95 (3) ◽  
pp. 876-884 ◽  
Author(s):  
N Oppenheimer-Marks ◽  
F Grinnell

Previous studies suggest that the baby hamster kidney (BHK) cell fibronectin receptor is also a wheat germ agglutinin receptor (WGA-R). To analyze this possibility further, IgG and Fab fragments of antibodies produced against a BHK cell WGA-R preparation were tested to determine their effects on cell adhesion mediated by fibronectin, wheat germ agglutinin, concanavalin A, and polycationic ferritin. The WGA-R preparation was isolated by octylglucoside extraction of BHK cells followed by chromatography of the extract on WGA-agarose. The antibodies against the WGA-R preparation reacted primarily with polypeptides of molecular weights 48, 61, 83, 105, 120, 165, 210, and 230 kilodaltons (kdaltons). It was concluded that the antibodies interfered with BHK cell fibronectin receptors on the basis of the ability of anti-WGA-R IgG or Fab fragments to (a) inhibit cell spreading on fibronectin-coated substrata; (b) cause rounding and detachment of cells previously spread on fibronectin-coated substrata; and (c) inhibit binding of fibronectin-coated latex beads to the cells. Antibody activity was blocked by treatment of anti-WGA-R with the WGA-R preparation or by absorption of anti-WGA-R with intact BHK cells. The antibodies also appeared to prevent coupling of ligand-receptor complexes (involving concanavalin A or polycationic ferritin) with the cytoskeleton. Finally, cell rounding and detachment caused by the antibodies were found to require metabolic energy since it did not occur in the presence of azide or at 4 degrees C.


Sign in / Sign up

Export Citation Format

Share Document