Mannose containing glycopeptides of cells derived from human teratocarcinoma (line PA 1)

1980 ◽  
Vol 58 (5) ◽  
pp. 384-393 ◽  
Author(s):  
Maija-Liisa Rasilo ◽  
Jorma Wartiovaara ◽  
Ossi Renkonen

Human teratocarcinoma derived cells, line PA 1, maintained in the undifferentiated state, yielded upon exhaustive pronase digestion unusually large glycopeptides (fraction A), which showed on gel filtration an apparent molecular weight larger than 7400. These glycopeptides derived from whole cell proteins carried large-sized oligosaccharides as evidenced by repeated pronase treatments, hydrazinolysis, and β-elimination experiments. The oligosaccharides consisted of mannose, fucose, galactose, and N-acetylglucosamine.The PA 1 cells contained also oligomannosyl type glycans, presumably linked to asparagine (fraction C glycopeptides). These glycopeptides were strongly bound to Con A – Sepharose and their oligosaccharides were released by endo-β-N-acetylglucosaminidase H. The liberated glycans ranged from Man5GlcNAc to Man9GlcNAc as analyzed by paper chromatography."Pulse–chase" experiments suggest that there is a precursor–product relationship between the mannose label in the fraction C (oligomannosyl type) glycopeptides and the fraction A glycopeptides.

1990 ◽  
Vol 63 (03) ◽  
pp. 499-504 ◽  
Author(s):  
A Electricwala ◽  
L Irons ◽  
R Wait ◽  
R J G Carr ◽  
R J Ling ◽  
...  

SummaryPhysico-chemical properties of recombinant desulphatohirudin expressed in yeast (CIBA GEIGY code No. CGP 39393) were reinvestigated. As previously reported for natural hirudin, the recombinant molecule exhibited abnormal behaviour by gel filtration with an apparent molecular weight greater than that based on the primary structure. However, molecular weight estimation by SDS gel electrophoresis, FAB-mass spectrometry and Photon Correlation Spectroscopy were in agreement with the theoretical molecular weight, with little suggestion of dimer or aggregate formation. Circular dichroism studies of the recombinant molecule show similar spectra at different pH values but are markedly different from that reported by Konno et al. (13) for a natural hirudin-variant. Our CD studies indicate the presence of about 60% beta sheet and the absence of alpha helix in the secondary structure of recombinant hirudin, in agreement with the conformation determined by NMR studies (17)


1976 ◽  
Vol 54 (2) ◽  
pp. 120-129 ◽  
Author(s):  
W. S. Rickert ◽  
P. A. McBride-Warren

The reaction of Mucor miehei protease with concanavalin A was followed by a turbidimetric assay in the pH range 5–8. At pH 4.0, no turbidity developed but binding of the enzyme to concanavalin A could be demonstrated by gel filtration. Two fractions of apparent molecular weight 65 000 and 52 000 were isolated, the 65 000 molecular weight species apparently representing a protomer of concanavalin A (24 000) bound to the enzyme. An analysis of the circular dichroism spectrum of this complex suggested that protomer binding results in a conformational change in the enzyme which is associated with a 30% increase in proteolytic activity.At pH 6.0, the enzyme was strongly bound to columns of concanavalin A Sepharose but could be removed by including α-methyl D-glucoside and NaCl in the elution buffer. Some column degradation occurred at room temperature but was not detectable at 4 °C where rapid elution of the enzyme resulted in a greater than 90% yield of highly active protein. Periodate-oxidized Mucor miehei protease and Mucor rennin did not react with concanavalin A and were not bound to the affinity column.


1976 ◽  
Vol 156 (1) ◽  
pp. 143-150 ◽  
Author(s):  
R H Quarles

Rats (14 days old) were injected with [14c]fucose and young adult rats with [3H]fucose in order to label the myelin-associated glycoproteins. As previously reported, the major [14C]fucose-labelled glycoprotein in the immature myelin had a higher apparent molecular weight on sodium dodecyl sulphate/polyacrylamide gels that the [3H]fucose-labelled glycoprotein in mature myelin. This predominant doubly labelled glycoprotein component was partially purified by preparative gel electrophoresis and converted to glycopeptides by extensive Pronase digestion. Gel filtration on Sephadex G-50 separated the glycopeptides into several clases, which were designted A,B, C AND D, from high to low molecular weight. The 14C-labelled glycopeptides from immature myeline were enriched in the highest-molecular-weight class A relative to the 3H-labelled glycopeptides from mature myelin. Neuraminidase treatment of the glycoprotein before Pronase digestion greatly decreased the proportion of glycopeptides fractionating in the higher-molecular-weight classes and largely eliminated the developmental differences that were apparent by gel filtration. However, neuraminidase treatment did not decrease the magnitude of the developmental difference revealed by electrophoresing the intact glycoprotein on sodium dodecyl sulphate gels, although it did decrease the apparent molecular weight of the glycoprotein from both the 15-day-old and adult rats by an amount comparable in magnitude to that developmental difference. The results from gel filtration of glycopeptides indicate that there is a higher content of large molecular weight, sialic acid-rich oligosaccharide units in the glycoprotein of immature myelin. However, the higher apparent molecular weight for the glycoprotein from 15-day-old rats on sodium dodcyl sulphate gels is not due primarily to its higher sialic acid content.


1997 ◽  
Vol 71 (3) ◽  
pp. 221-226 ◽  
Author(s):  
M. Owhashi ◽  
Y. Horii ◽  
A. Ishii

AbstractThe relationship between the cercarial allergen and two previously isolated egg allergens (J1, J2) of Schistosoma japonicum was examined especially in terms of the cross-reactivity between them. Semi-purified cercarial allergen (JAC) was obtained from the crude extract of S. japonicum cercariae by gel chromatography on Sephadex G-200. The apparent molecular weight of JAC was estimated approximately as 60–100 kDa. JAC could bind to Con A-Sepharose, indicating its glycoprotein nature. Three groups of BALB/c mice were immunized with JAC, J1 or J2 using A1(OH)3 as adjuvant, and the cross-reactivity of each antiserum was examined by PCA. Anti-JAC, anti-Jl or anti-J2 serum was highly specific to the corresponding antigen. When IgE-ELISA of S. japonicum patient sera was performed using JAC, J1 or J2 as an antigen, the correlation between anti-J1 and anti-J2 (r = 0.78) was high, whereas the correlation between anti-JAC and anti-J1 (r = 0.27) or between anti-JAC and anti-J2 (r = 0.12) was low. These results suggest that most IgE epitopes on cercarial allergen are independent from those on egg allergens in S. japonicum.


1976 ◽  
Vol 36 (1) ◽  
pp. 101-112 ◽  
Author(s):  
I. Bremner ◽  
N. T. Davies

1. A study has been made by gel-filtration techniques of the soluble copper- and zinc-binding proteins in rat liver after both intraperitoneal injection of Cu and dietary Cu supplementation.2. Liver Cu and Zn concentrations increased after injection of Cu, both metals accumulating in the cytosol, mainly in a fraction with an apparent molecular weight of (about 12 000)3. When Zn-deficient rats were injected with Cu, there was little change in liver Zn concentration and the occurrence of Cu in the low-molecular-weight form (about 12 000) was more transient. At most periods after injection, Cu accumulated mainly in a fraction with a molecular weight greater than 65 000.4. When the rats were Cu-loaded by dietary supplementation, virtually no Cu or Zn was found in the low-molecular-weight form in Zn-deficient rats, although they were found in the Zn-supplemented animals.5. The results suggest that Zn is essential for the accumulation of Cu in this form, but not for Cu to stimulate production of the metal-binding protein by a process requiring active protein synthesis.


1993 ◽  
Vol 2 (6) ◽  
pp. 447-452 ◽  
Author(s):  
M. R. Daha ◽  
L. Dunn ◽  
R. van den Berg ◽  
Y. Muizert-de Lange ◽  
A. Gerritsen ◽  
...  

It has been shown previously that cultured human venous and arterial endothelial cells (EC) bind C1q in a time- and dose-dependent manner. Cultured human endothelial cells express an average number of 5.2 × 105binding sites/cell. In the present study the putative receptor for C1q (C1qR) was isolated from the membranes of 1–5 × 109human umbilical cord EC by affinity chromatography on C1q–Sepharose. During isolation, C1qR was detected by its capacity to inhibit the lysis of EAC1q in C1q-deficient serum. The eluate from C1q–Sepharose was concentrated, dialysed and subjected to QAE-A50 chromatography and subsequently to gel filtration on HPLC–TSK 3000. C1qR filtered at an apparent molecular weight of 60 kDa. Purified C1qR exhibited an apparent molecular weight of 55–62 kDa in the unreduced state and a molecular weight of 64–68 kDa in reduced form. Two IgM monoclonal antibodies (mAb) D3 and D5 were raised following immunization of mice with purified receptor preparations. Both monoclonal antibodies increased the binding of125I-C1q to endothelial cells but F(ab')2anti-C1qR mAb inhibited the binding of a125I-C1q to EC in a dosedependent manner. The D3 mAb recognized a band of 54–60 kDa in Western blots of membranes of human EC and polymorphonuclear leukocytes. Previously, the authors showed that C1q induces the binding of IgM-containing immune complexes to EC. Therefore, it was hypothesized that during a primary immune response generation of IgM-IC may occur, resulting in binding and activation of C1, dissociation of activated C1 by C1 inhibitor and subsequent interaction of IgM-IC bearing C1q with EC–C1qR.


Blood ◽  
1983 ◽  
Vol 61 (5) ◽  
pp. 960-966 ◽  
Author(s):  
T Hoang ◽  
NN Iscove ◽  
N Odartchenko

Abstract The relationship between molecules having granulocyte colony- stimulating activity (G-CSA), erythroid burst-promoting activity (E- BPA), and activity promoting increase in the number of granulocytic progenitors in liquid culture (delta GPA) was explored in conditioned medium from human leukocytes (HLCM) and human placenta (HPCM). As tested on human hemopoietic progenitors in culture, G-CSA eluted from Sephadex G100 as a single peak with apparent molecular weight of 25,000, separating partially from E-BPA and delta GPA, which both had an apparent molecular weight of 45,000. All three activities eluted together from hydroxyapatite at low molarity phosphate. Their charge properties were also similar and all three electrofocused in flat gel beds in the pH range near 5.4. On both hydroxyapatite and isoelectric focusing, delta GPA sometimes separated partially from the other two activities but not consistently. The gel filtration result shows that in conditioned medium of human origin, molecules having G-CSA are not the same as those having delta GPA, suggesting a dual factor requirement in the granulocytic lineage reminiscent of that in the erythroid pathway. The results suggesting that delta GPA might differ from E-BPA, on the other hand, were not consistent enough to establish their nonidentity. Single micromanipulated cells proved capable of forming erythroid or granulocytic colonies in the presence of either crude or partially purified activity. The results establish that human colony-forming cells are direct primary targets of growth factors in HLCM and HPCM.


1975 ◽  
Author(s):  
J. D. Olson ◽  
D. N. Fass ◽  
W. J. Brockway ◽  
E. J. W. Bowie ◽  
K. G. Mann

A component required for the ristocetin-induced aggregation of platelets was isolated in yields of 20-30% from pooled human and porcine plasma by cryoethanol concentration of the RWF, after removal of the vitamin K dependent coagulation factors on barium citrate. The concentrate was further purified using gel filtration (4% agarose) and ion exchange (DEAE-cellulose) chromatography. Sodium dodecyl sulfate polyacrylamide gels of the isolated factor indicated an apparent molecular weight of greater than 500,000. After reduction of RWF with mercaptoethanol, a single band is resolved with an apparent molecular weight of 230,000. The purified component had no factor VIII procoagulant activity and did not compete for the activity of naturally occurring factor VIII inhibitor (human). Antisera raised in rabbits directed against the purified component inhibited the RWF activity but not the factor VIII procoagulant activity of plasma. Amino acid analysis indicated the presence of all normal amino acids and failed to detect any amino sugar. Analysis of lipid revealed a significant amount of lipid composed of mono, di and triglycerides, cholesterol, cholesterol esters and free fatty acid, with small portions of phospholipids.


1996 ◽  
Vol 51 (5-6) ◽  
pp. 429-431 ◽  
Author(s):  
M.O. Ilori ◽  
O.O. Amund ◽  
O. Omidiji

Abstract A proteolytic enzyme produced by a cassava-ferment­ing strain of Micrococcus luteus was extracted and puri­fied 50-fold by gel filtration and ion exchange chromatography. The optimum pH for the enzyme was 7.0, the optimum temperature 25 °C, the apparent molecular weight 42 kDa and the Km value, 0.45 mg ml-1 with casein as substrate. The enzyme was stimulated by Ca2+ and Mg2+ but inhibited by Zn2+ and Co2+ ions. Other inhibitors were EDTA, KCN, citric acid and L-cysteine indicating the enzyme to be a metalloprotease.


1981 ◽  
Author(s):  
R E Benson ◽  
W J Dodds

Previous studies demonstrated that plasma from dogs homozygous for von Willebrand’s disease (VWD) without detectable factor VUI-related antigen (VIII:RAg) contained moderate levels of a stable factor VIH-coagulant (VIII:C), which had lower apparent molecular weight and combined with the VIII:RAg of canine hemophilic plasma. We have now compared this VWD-VIII:C to the CaCl2-separated form of VIII:C prepared from normal canine factor VIII. The VWD plasma was fractionated at room temperature by 6% agarose gel filtration in 0.15M NaCl and 0.24M CaCl2 buffers, pH 7.25; the VIII:C eluted in each buffer with a relative elution volume (Ve/Vo) of 1.4. Isolated lower molecular weight VIII:C stabilized with albumin (5 mg/ml) and dialysed free of Ca++ was prepared from normal purified canine factor VIII by elution in 0.24M CaCl2 buffer. This CaCl2~separated VIII:C was rechromatographed in both buffers as above and had a Ve/Vo of 1.9. When the VWD and CaCl2 forms of VIII:C were each combined with canine hemophilic plasma and gel filtered in 0.15M NaCl buffer, the VIII:C’s now appeared at the void volume. These mixtures with 1/10 volume 2.4M CaCl2 added before or after combination were also analyzed in 0.24M CaCl2 buffer. The CaCl2-VIII:C eluted with a Ve/Vo of 1.9 regardless of the order of 2.4M CaCl2 addition, but the VWD-VIII:C eluted with Ve/Vo’s of 1.4 when CaCl2 was added before mixing and 1.9 when added afterwards.Thus, when mixed with hemophilic plasmas both the CaCl2 and VWD forms of VIII:C exhibited similar combination and separation characteristics. However, the finding that the CaCl2-VIII:C is of apparent lower molecular weight than the VWD form suggests that the CaCl2-separated VIII:C is different from the naturally occurring form of VWD (VIII: RAg-free) VIII:C.


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