scholarly journals Assessment of Sialic Acid Diversity in Cancer- and Non-Cancer Related CA125 Antigen Using Sialic Acid-Binding Ig-Like Lectins (Siglecs)

2012 ◽  
Vol 32 (3) ◽  
pp. 187-194 ◽  
Author(s):  
N. Mitic ◽  
B. Milutinovic ◽  
M. Jankovic
Keyword(s):  
Sialic Acid ◽  
Ovarian Carcinoma ◽  
Solid Phase ◽  
Tumour Marker ◽  
Sialic Acids ◽  
Binding Assays ◽  
Ovarian Carcinoma Cell Line ◽  
Sialic Acid Binding ◽  
Solid Phase Binding ◽  
Different Origin

This study was aimed at obtaining insight into the diversity of sialic acids in cancer- and non-cancer-related CA125 antigen, tumour marker of serous ovarian cancer. Starting from available data suggesting the possible relevance of sialic acids for discriminating CA125 antigens of different origin, we have employed a new experimental approach based on the use of human sialic acid-binding Ig-like lectins, Siglecs, as tools for the investigation of sialylation.Siglec−2, belonging to the group of evolutionarily conserved Siglecs, and Siglec−3, −6, −7, −9 and −10, which are CD33-like Siglecs, were probed in solid-phase binding assays with cancer-related CA125 antigens from pleural fluid of patients with ovarian carcinoma (pfCA125), the OVCAR-3 ovarian carcinoma cell line (clCA125) and a non-cancer-related CA125 antigen, i.e. pregnancy-associated pCA125 antigen.All Siglecs used showed detectable binding to pCA125 antigen. Siglec−3, Siglec−7 and Siglec−2 exhibited moderately stronger binding to pCA125 antigen than the others. In contrast to this, Siglec−2 and Siglec−3 preferentially recognized pfCA125 with greater total binding than for pCA125, whereas Siglec−9 and Siglec−10 were highly selective for clCA125.Siglecs promise to be powerful tools for discriminating CA125 of different origin and could propagate further research on other molecular markers of biomedical and diagnostic importance.

Ability of PknA, a mycobacterial eukaryotic-type serine/threonine kinase, to transphosphorylate MurD, a ligase involved in the process of peptidoglycan biosynthesis

2008 ◽  
Vol 415 (1) ◽  
pp. 27-33 ◽  
Author(s):  
Meghna Thakur ◽  
Pradip K. Chakraborti
Keyword(s):  
Protein Kinases ◽  
Solid Phase ◽  
Morphological Changes ◽  
Binding Assays ◽  
Serine Threonine Kinase ◽  
Threonine Kinase ◽  
Peptidoglycan Biosynthesis ◽  
Vitro Binding ◽  
Solid Phase Binding

Eukaryotic-type serine/threonine protein kinases in bacteria have been implicated in controlling a host of cellular activities. PknA is one of eleven such protein kinases from Mycobacterium tuberculosis which regulates morphological changes associated with cell division. In the present study we provide the evidence for the ability of PknA to transphosphorylate mMurD (mycobacterial UDP-N-acetylmuramoyl-L-alanine:D-glutamate-ligase), the enzyme involved in peptidoglycan biosynthesis. Its co-expression in Escherichia coli along with PknA resulted in phosphorylation of mMurD. Consistent with these observations, results of the solid-phase binding assays revealed a high-affinity in vitro binding between the two proteins. Furthermore, overexpression of m-murD in Mycobacterium smegmatis yielded a phosphorylated protein. The results of the present study therefore point towards the possibility of mMurD being a substrate of PknA.

scholarly journals Automated solid-phase synthesis of oligosaccharides containing sialic acids

2015 ◽  
Vol 11 ◽  
pp. 617-621 ◽  
Author(s):  
Chian-Hui Lai ◽  
Heung Sik Hahm ◽  
Chien-Fu Liang ◽  
Peter H Seeberger
Keyword(s):  
Sialic Acid ◽  
Building Block ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Sialic Acids ◽  
Phase Synthesis ◽  
Glycosyl Phosphate

A sialic acid glycosyl phosphate building block was designed and synthesized. This building block was used to prepare α-sialylated oligosaccharides by automated solid-phase synthesis selectively.

scholarly journals Porcine Arterivirus Infection of Alveolar Macrophages Is Mediated by Sialic Acid on the Virus

2004 ◽  
Vol 78 (15) ◽  
pp. 8094-8101 ◽  
Author(s):  
Peter L. Delputte ◽  
Hans J. Nauwynck
Keyword(s):  
Sialic Acid ◽  
Alveolar Macrophages ◽  
Sialic Acids ◽  
Respiratory Syndrome Virus ◽  
Specific Monoclonal Antibody ◽  
Neuraminidase Treatment ◽  
Acid Binding Protein ◽  
Sialic Acid Binding ◽  
High Mannose ◽  
Binding Lectin

ABSTRACT Recently, we showed that porcine sialoadhesin (pSn) mediates internalization of the arterivirus porcine reproductive and respiratory syndrome virus (PRRSV) in alveolar macrophages (Vanderheijden et al., J. Virol. 77:8207-8215, 2003). In rodents and humans, sialoadhesin, or Siglec-1, has been described as a macrophage-restricted molecule and to specifically bind sialic acid moieties. In the current study, we investigated whether pSn is a sialic acid binding protein and, whether so, whether this property is important for its function as a PRRSV receptor. Using untreated and neuraminidase-treated sheep erythrocytes, we showed that pSn binds sialic acid. Furthermore, pSn-specific monoclonal antibody 41D3, which blocks PRRSV infection, inhibited this interaction. PRRSV attachment to and infection of porcine alveolar macrophages (PAM) were both shown to be dependent on the presence of sialic acid on the virus: neuraminidase treatment of virus but not of PAM blocked infection and reduced attachment. Enzymatic removal of all N-linked glycans on the virus with N-glycosidase F reduced PRRSV infection, while exclusive removal of nonsialylated N-linked glycans of the high-mannose type with endoglycosidase H had no significant effect. Free sialyllactose and sialic acid containing (neo)glycoproteins reduced infection, while lactose and (neo)glycoproteins devoid of sialic acids had no significant effect. Studies with linkage-specific neuraminidases and lectins indicated that α2-3- and α2-6-linked sialic acids on the virion are important for PRRSV infection of PAM. From these results, we conclude that pSn is a sialic acid binding lectin and that interactions between sialic acid on the PRRS virion and pSn are essential for PRRSV infection of PAM.

Ultrastructural Evidence for Proteoglycans Mediating an Attachment of Type VI Collagen to Banded Collagen Fibrils

1997 ◽  
Vol 3 (S2) ◽  
pp. 153-154
Author(s):  
Douglas R. Keene ◽  
Catherine C. Ridgway ◽  
Renato V. Iozzo
Keyword(s):  
Dermatan Sulfate ◽  
Core Protein ◽  
Solid Phase ◽  
Collagen Fibrils ◽  
Binding Assays ◽  
Connective Tissues ◽  
Type Vi Collagen ◽  
Dermatan Sulfate Proteoglycan ◽  
Individual Type ◽  
Solid Phase Binding

Immunolocalizaton studies of type VI collagen in skin have previously demonstrated that type VI collagen forms a flexible network that anchors large interstitial structures such as nerves, blood vessels, and collagen fibers into the surrounding connective tissues matrix. The purpose of this study is to determine if individual type VI collagen microfilaments might be connected to banded collagen fibrils, thereby stabilizing the network.Solid phase binding assays suggest a specific, high affinity interaction between the core protein of the dermatan sulfate proteoglycan decorin and type VI collagen, and immunocytochemical studies in fetal and neonate rabbit cornea suggest an association of decorin with type VI microfilaments. Other studies in skin and perichondrium have localized decorin to a region between the d and e bands of banded collagen fibrils. However, no direct documentation has demonstrated a specific structural interaction between type VI microfilaments and banded collagen fibrils. We, therefore, sought to determine if type VI microfilaments cross banded collagen fibrils between the “d” and “e” bands.

scholarly journals Fibulin-1 mediates platelet adhesion via a bridge of fibrinogen

Blood ◽  
1996 ◽  
Vol 88 (7) ◽  
pp. 2569-2577 ◽  
Author(s):  
S Godyna ◽  
M Diaz-Ricart ◽  
WS Argraves
Keyword(s):  
Extracellular Matrix ◽  
Vascular Injury ◽  
Whole Blood ◽  
Platelet Adhesion ◽  
Solid Phase ◽  
Blood Perfusion ◽  
General Mechanism ◽  
Binding Assays ◽  
Solid Phase Binding ◽  
Coated Surfaces

Fibulin-1 is a component of the extracellular matrix that surrounds vascular smooth muscle. This observation, along with the recent finding that fibulin-1 can bind fibrinogen (J Biol Chem 270:19458, 1995), prompted investigation into the potential role of fibulin-1 as a thrombogenic agent. In perfusion chamber assays, platelets in whole blood under flow conditions attached and spread on surfaces coated with fibulin-1. This adhesion was completely blocked by fibulin-1 antibodies. Platelets free of plasma did not attach to fibulin-1 coated surfaces; however, with the addition of fibrinogen, platelet adhesion to fibulin-1 took place. When detergent extracts of platelets were subjected to fibulin-1-Sepharose affinity chromatography, the integrin alpha IIb beta 3 was selected. Solid phase binding assays using purified components showed that integrin alpha IIb beta 3 could not bind directly to fibulin-1 but in the presence of fibrinogen the integrin bound to fibulin-1-coated surfaces. Monoclonal alpha IIb beta 3 antibodies capable of blocking its interaction with fibrinogen completely blocked platelet adhesion to fibulin-1 in both whole blood perfusion and static adhesion assays. The results show that fibulin-1 can support platelet attachment via a bridge of fibrinogen to the platelet integrin alpha IIb beta 3. When fibroblast monolayers containing extracellular matrix-incorporated fibulin-1 were used as adhesion substrates, platelet adhesion in the presence of fibrinogen could be inhibited by 30% using antibodies to fibulin-1. Following vascular injury, fibulin-1 present in the extracellular matrix of the vessel wall may therefore interact with plasma fibrinogen and promote platelet adhesion, leading to the formation of a platelet plug. Thus, fibulin-1 joins the list of matrix proteins including collagens I and IV and fibronectin that mediate platelet adhesion via a plasma protein bridge. This bridging phenomenon may represent a general mechanism by which platelets interact with exposed subendothelial matrices following vascular injury.

Immobilized whole algal cells for solid-phase binding assays

1986 ◽  
Vol 86 (2) ◽  
pp. 171-177 ◽  
Author(s):  
Paul Bubrick ◽  
Leon Goldstein ◽  
Asher Frensdorff
Keyword(s):  
Solid Phase ◽  
Binding Assays ◽  
Solid Phase Binding

Production of transferrin receptors byHistophilus ovis: three of five strains require two signals

2001 ◽  
Vol 47 (5) ◽  
pp. 417-423 ◽  
Author(s):  
Andrew Ekins ◽  
Donald F Niven
Keyword(s):  
Solid Phase ◽  
Iron Acquisition ◽  
Isolation Procedure ◽  
Transferrin Receptors ◽  
Binding Assays ◽  
Surface Receptors ◽  
Iron Restriction ◽  
Affinity Isolation ◽  
Solid Phase Binding ◽  
Bovine Transferrin

Five strains of Histophilus ovis (9L, 642A, 714, 5688T, and 3384Y) were investigated with respect to iron acquisition. All strains used ovine, bovine, and goat transferrins (Tfs), but not porcine or human Tfs, as iron sources for growth. In solid phase binding assays, total membranes from only two (9L and 642A) of the five strains, grown under iron-restricted conditions, were able to bind Tfs (ovine, bovine, and goat, but not porcine or human). However, when the organisms were grown under iron-restricted conditions in the presence of bovine transferrin (Tf), total membranes from all strains exhibited Tf binding (as above); competition experiments demonstrated that all three Tfs (ovine, bovine, and goat) were bound by the same receptor(s). Membranes from organisms grown under iron-replete conditions in the presence or absence of bovine Tf failed to bind any of the test Tfs. An affinity-isolation procedure allowed the isolation of two putative Tf-binding polypeptides (78 and 66 kDa) from total membranes of strains 9L and 642A grown under iron-restricted conditions, and from membranes of all strains if the growth medium also contained Tf. It is concluded that all strains tested acquire Tf-bound iron by means of siderophore-independent mechanisms involving surface receptors analogous to the Tf-binding proteins (TbpA and TbpB) found in comparable organisms; although iron restriction alone is sufficient to promote the expression of these proteins by strains 9L and 642A, their production by strains 714, 5688T, and 3384Y appears to require two signals, iron restriction and the presence of Tf.Key words: Histophilus ovis, iron acquisition, transferrins, receptors, regulation.

New insights into the structural elements involved in the skin haemorrhage induced by snake venom metalloproteinases

2010 ◽  
Vol 104 (09) ◽  
pp. 485-497 ◽  
Author(s):  
Ana Oliveira ◽  
Adriana Paes Leme ◽  
Amanda Asega ◽  
Antonio Camargo ◽  
Jay Fox ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Snake Venom ◽  
Solid Phase ◽  
Structural Elements ◽  
Binding Assays ◽  
Domain Organisation ◽  
Solid Phase Binding ◽  
A Minor ◽  
Von Willebrand

SummaryHaemorrhage induced by snake venom metalloproteinases (SVMPs) is a complex phenomenon resulting in capillary disruption and extravasation. This study analysed structural elements important for the interaction of four Bothrops jararaca SVMPs of different domain organisation and glycosylation levels with plasma and extracellular matrix proteins: HF3 (P-III class) is highly glycosylated and ~80 times more haemorrhagic than bothropasin (P-III class), which has a minor carbohydrate moiety; BJ-PI (P-I class) is not haemorrhagic and the DC protein is composed of disintegrin-like/cysteine-rich domains of bothropasin. HF3, bothropasin and BJ-PI showed different degradation profiles of fibrinogen, fibronectin, vitronectin, von Willebrand factor, collagens IV and VI, laminin and Matrigel™; however, only bothropasin degraded collagen I. In solid-phase binding assays HF3 and bothropasin interacted with fibrinogen, fibronectin, laminin, collagens I and VI; the DC protein bound only to collagens I and VI; however, no binding of BJ-PI to these proteins was detected. N-deglycosylation caused loss of structural stability of bothropasin and BJ-PI but HF3 remained intact, although its haemorrhagic and fibrinogenolytic activities were partially impaired. Nevertheless, N-deglycosylated HF3 bound with higher affinity to collagens I and VI, although its proteolytic activity upon these collagens was not enhanced. This study demonstrates that features of carbohydrate moieties of haemorrhagic SVMPs may play a role in their interaction with substrates of the extracellular matrix, and the ability of SVMPs to degrade proteins in vitro does not correlate to their ability to cause haemorrhage, suggesting that novel, systemic approaches are necessary for understanding the mechanism of haemorrhage generation by SVMPs.

scholarly journals A Myopathy-linked Desmin Mutation Perturbs Striated Muscle Actin Filament Architecture

2009 ◽  
Vol 20 (3) ◽  
pp. 834-845 ◽  
Author(s):  
Gloria M. Conover ◽  
Syerra N. Henderson ◽  
Carol C. Gregorio
Keyword(s):  
Actin Filament ◽  
Thin Filament ◽  
Striated Muscle ◽  
Solid Phase ◽  
Skeletal Muscle Atrophy ◽  
Binding Assays ◽  
Concomitant Increase ◽  
Solid Phase Binding ◽  
Intracellular Aggregates ◽  
Filament Network

Desmin interacts with nebulin establishing a direct link between the intermediate filament network and sarcomeres at the Z-discs. Here, we examined a desmin mutation, E245D, that is located within the coil IB (nebulin-binding) region of desmin and that has been reported to cause human cardiomyopathy and skeletal muscle atrophy. We show that the coil IB region of desmin binds to C-terminal nebulin (modules 160-164) with high affinity, whereas binding of this desmin region containing the E245D mutation appears to enhance its interaction with nebulin in solid-phase binding assays. Expression of the desmin-E245D mutant in myocytes displaces endogenous desmin and C-terminal nebulin from the Z-discs with a concomitant increase in the formation of intracellular aggregates, reminiscent of a major histological hallmark of desmin-related myopathies. Actin filament architecture was strikingly perturbed in myocytes expressing the desmin-E245D mutant because most sarcomeres contained elongated or shorter actin filaments. Our findings reveal a novel role for desmin intermediate filaments in modulating actin filament lengths and organization. Collectively, these data suggest that the desmin E245D mutation interferes with the ability of nebulin to precisely regulate thin filament lengths, providing new insights into the potential molecular consequences of expression of certain disease-associated desmin mutations.

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