High molecular mass glycoproteins associated with the siliceous scales and bristles of Mallomonas splendens (Synurophyceae) may be involved in cell surface development and maintenance

Planta ◽  
1996 ◽  
Vol 199 (2) ◽  
Author(s):  
Martha Ludwig ◽  
JanL. Lind ◽  
ElizabethA. Miller ◽  
Richard Wetherbee
Keyword(s):  
Cell Surface ◽  
Molecular Mass ◽  
High Molecular Mass ◽  
Surface Development

A dolichol acyltransferase present in rat and human postheparin plasma

1992 ◽  
Vol 70 (6) ◽  
pp. 470-474 ◽  
Author(s):  
P. Sindelar ◽  
C. Valtersson
Keyword(s):  
Cell Surface ◽  
Molecular Mass ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
High Molecular Mass ◽  
Gel Chromatography ◽  
Heat Treated ◽  
A Cell ◽  
Small Unilamellar Vesicles ◽  
Plasma Heparin

Incubation of small unilamellar vesicles consisting of dioleoyl phosphatidylcholine – dioleoyl phosphatidylethanolamine (3:1) and 2 mol% [3H]dolichol-19 with postheparin plasma from rat resulted in the formation of dolichyl oleate. Normal plasma or heat-treated postheparin plasma contained no activity and, hence, the results indicate the presence of a cell surface associated dolichol acyltransferase that can be released into the blood by heparin. The reaction is strongly stimulated by phosphatidylethanolamine and Ca2+, whereas no stimulation with triglycerides or acyl-CoA was observed. Together with the fact that the only product formed was dolichyl oleate, these results strongly suggest that a transacylation mechanism from the phospholipids to dolichol is operative in the liposomes. Gel chromatography of postheparin plasma yielded a molecular mass of about 350 kilodaltons for the active enzyme and density gradient centrifugation indicated that this high molecular mass complex consists mainly of proteins. Finally, we conclude that this enzyme is not unique to the rat, but is also present in human postheparin plasma.Key words: phospholipids, dolichol, plasma, heparin, acyltransferase(s).

Biosynthesis and shedding of epiglycanin: a mucin-type glycoprotein of the mouse TA3Ha mammary carcinoma cell

2000 ◽  
Vol 353 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Torunn THINGSTAD ◽  
Hans L. VOS ◽  
John HILKENS
Keyword(s):  
Cell Surface ◽  
Molecular Mass ◽  
Biological Function ◽  
Carcinoma Cell ◽  
High Molecular Mass ◽  
Mammary Carcinoma Cell ◽  
Mature Form ◽  
Cell Matrix ◽  
Long Rod ◽  
Cell Matrix Adhesion

Epiglycanin is a mucin-type glycoprotein present at the surface of TA3Ha mouse mammary tumour cells. It is a long rod-like glycoprotein with a molecular mass of 500kDa. Its function has not yet been established but its overexpression can affect cell–cell and cell–matrix adhesion. To understand better the biological function of epiglycanin, we have studied the biochemical structure and biosynthesis of epiglycanin in TA3Ha cells. Pulse–chase labelling experiments with [3H]threonine revealed an early precursor with a molecular mass of approx. 300kDa containing approx. 5–10kDa of N-linked glycans. The precursor was gradually converted into a high-molecular-mass mature form, owing mainly, if not entirely, to O-glycosylation. The mature molecule consists of two major glycoforms that differ in sialylation. Unlike secreted mucins, epiglycanin did not form cysteine-bound multimers, providing further evidence that epiglycanin belongs to the class of membrane-associated mucins. The mature form, but not the precursor form, is shed from the cell surface. The half-life of epiglycanin on the cell surface was found to be approx. 60h. These results provide the first detailed analysis of the biochemical structure and biosynthesis of epiglycanin.

scholarly journals Binding of Transmissible Gastroenteritis Coronavirus to Cell Surface Sialoglycoproteins

2002 ◽  
Vol 76 (12) ◽  
pp. 6037-6043 ◽  
Author(s):  
Christel Schwegmann-Weßels ◽  
Gert Zimmer ◽  
Hubert Laude ◽  
Luis Enjuanes ◽  
Georg Herrler
Keyword(s):  
Sialic Acid ◽  
Cell Surface ◽  
Molecular Mass ◽  
Cultured Cells ◽  
Binding Activity ◽  
High Molecular Mass ◽  
Parental Virus ◽  
Transmissible Gastroenteritis Virus ◽  
Sialic Acid Binding ◽  
Transmissible Gastroenteritis

ABSTRACT The surface glycoprotein S of transmissible gastroenteritis virus (TGEV) has two binding activities. (i) Binding to porcine aminopeptidase N (pAPN) is essential for the initiation of infection. (ii) Binding to sialic acid residues on glycoproteins is dispensable for the infection of cultured cells but is required for enteropathogenicity. By comparing parental TGEV with mutant viruses deficient in the sialic acid binding activity, we determined the contributions of both binding activities to the attachment of TGEV to cultured cells. In the presence of a functional sialic acid binding activity, the amount of virus bound to two different porcine cell lines was increased sixfold compared to the binding of the mutant viruses. The attachment of parental virus was reduced to levels observed with the mutants when sialic acid containing inhibitors was present or when the cells were pretreated with neuraminidase. In virus overlay binding assays with immobilized cell surface proteins, the mutant virus only recognized pAPN. In addition, the parental virus bound to a high-molecular-mass sialoglycoprotein. The recognition of pAPN was sensitive to reducing conditions and was not dependent on sialic acid residues. On the other hand, binding to the sialic acid residues of the high-molecular-mass glycoprotein was observed regardless of whether the cellular proteins had been separated under reducing or nonreducing conditions. We propose that binding to a surface sialoglycoprotein is required for TGEV as a primary attachment site to initiate infection of intestinal cells. This concept is discussed in the context of other viruses that use two different receptors to infect cells.

scholarly journals Binding of human plasminogen and high-molecular-mass kininogen by cell surface-exposed proteins of Candida parapsilosis

2017 ◽  
Vol 64 (3) ◽  
pp. 391-400 ◽  
Author(s):  
Justyna Karkowska-Kuleta ◽  
Dorota Zajac ◽  
Grazyna Bras ◽  
Oliwia Bochenska ◽  
Maria Rapala-Kozik ◽  
...  
Keyword(s):  
Cell Surface ◽  
Molecular Mass ◽  
Candida Parapsilosis ◽  
High Molecular Mass ◽  
Human Plasminogen

scholarly journals Characterization of the interactions between human high-molecular-mass kininogen and cell wall proteins of pathogenic yeasts, Candida tropicalis

2016 ◽  
Vol 63 (3) ◽  
Author(s):  
Justyna Karkowska-Kuleta ◽  
Dorota Zajac ◽  
Grazyna Bras ◽  
Oliwia Bochenska ◽  
Karolina Seweryn ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Surface ◽  
Molecular Mass ◽  
Candida Tropicalis ◽  
Dissociation Constants ◽  
High Molecular Mass ◽  
Biologically Active ◽  
Phosphoglycerate Mutase ◽  
Cell Wall Proteins ◽  
Effective Prevention

Candida tropicalis is one of the most frequent causes of serious, disseminated candidiasis in human patients infected by non-albicans Candida species, but still relatively little is known about its virulence mechanisms. In our current study, the interactions between the cell surface of this species and a multifunctional human protein—high-molecular-mass kininogen (HK), an important component of the plasma contact system involved in the development of the inflammatory state—were characterized at the molecular level. The quick release of biologically active kinins from candidal cell wall-adsorbed HK was presented and the HK-binding ability was assigned to several cell wall-associated proteins. Predicted hyphally regulated cell wall protein (Hyr) and some housekeeping enzymes exposed at the cell surface (known as “moonlighting proteins”) were found to be the major HK binders. Accordingly, after purification of selected proteins, the dissociation constants of the complexes of HK with Hyr, enolase and phosphoglycerate mutase were determined using surface plasmon resonance measurements, giving the values of 2.20 x 10-7 M, 1.42 x 10-7 M and 5.81 x 10-7 M, respectively. Therefore, in this work, for the first time, the interactions between C. tropicalis cell wall proteins and HK were characterized in molecular terms. Our findings may be useful for designing more effective prevention and treatment approaches against infections caused by this dangerous fungal pathogen.

High molecular mass kininogen inhibits cathepsin G-induced platelet activation by forming a complex with cathepsin G

2001 ◽  
Vol 2 (6) ◽  
pp. 371-377 ◽  
Author(s):  
Tarek E Selim ◽  
Hayam R Ghoneim ◽  
Hassan A Abdel Ghaffar ◽  
Robert W Colman ◽  
Raul A Dela Cadena
Keyword(s):  
Molecular Mass ◽  
Platelet Activation ◽  
High Molecular Mass ◽  
Cathepsin G
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