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Paul Muralt - One of the best experts on this subject based on the ideXlab platform.
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piezoelectric and structural properties of c axis textured aluminium scandium nitride thin films up to high scandium content
Surface & Coatings Technology, 2018Co-Authors: Stefan Mertin, Oliver Rattunde, Sylvain Nicolay, Gabriel Christmann, Bernd Heinz, Marc Dubois, Paul MuraltAbstract:Abstract Partial substitution of aluminium by scandium in the wurtzite structure of aluminium nitride (AlN) leads to a large increase of the piezoelectric response by more than a factor of 2. Therefore, aluminium scandium nitride (ASN) thin films attracted much attention to improve piezoelectric MEMS devices such as RF filters, sensors, micro actuators and energy harvesting devices. In this work, process-microstructure-property relationships of ASN thin films containing up to 42% Sc were investigated. Like AlN thin films, ASN films are sputter deposited at 300–350°C with pulsed DC powered magnetrons. The influence of the process parameters on the film structure, the intrinsic stress and the piezoelectric response was investigated in order to achieve optimal piezoelectric coefficients up to high Sc concentrations. X-Ray diffraction (XRD) and transmission electron microscopy (TEM) were used to analyse the quality of c-axis texture. The films showed exclusively (002) texture with rocking-curve widths in the range of 1.3–2° (FHWM). The films were further analysed by scanning electron microscopy (SEM). The Sc content was determined by energy-dispersive X-ray spectroscopy (EDX). A good compositional homogeneity in the range of 0.5–1 at.% was achieved between border and centre of 200-mm wafers. So far, we obtained ASN films with transversal piezoelectric coefficients of up to e31,f = −2.77 C/m2, which is a factor 2.6 higher than in pure AlN thin films.
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enhanced piezoelectric properties of c axis textured aluminium scandium nitride thin films with high scandium content influence of intrinsic stress and sputtering parameters
Internaltional Ultrasonics Symposium, 2017Co-Authors: Stefan Mertin, Oliver Rattunde, Marc Alexandre Dubois, Gabriel Christmann, Bernd Heinz, Vladimir Pashchenko, Fazel Parsapour, Clemens Nyffeler, Cosmin S. Sandu, Paul MuraltAbstract:Aluminium scandium nitride (ASN) exhibits a largely enhanced piezoelectric response as compared to aluminium nitride (AlN), which makes it an upcoming piezoelectric material for use in next generation RF filters, sensors, actuators and energy harvesting devices. In this work, process-microstructure-property relationships of such sputtered ASN films containing up to 42 at% Sc were investigated. Hereby, the influence of the process parameters on the film structure, the intrinsic stress and the piezoelectric response were carefully investigated. A high piezoelectric response (e 31, f = −2.67 C/m2 and d 33, f = 10.3 pm/V) was measured for films with 42 at% and 34 at% Sc, respectively. The results are very promising towards industrial applications.
Edda Töpfer-petersen - One of the best experts on this subject based on the ideXlab platform.
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Monoclonal antibodies against boar sperm zona pellucida-binding protein Awn-1. Characterization of a continuous antigenic determinant and immunolocalization of Awn epitopes in inseminated sows.
Biology of reproduction, 1997Co-Authors: Juan J. Calvete, Libia Sanz, Edda Töpfer-petersen, Knut Adermann, Paz Martínez, Michael Ensslin, Jane Mburu, Antonio Iborra, Dagmar Waberski, K. F. WeitzeAbstract:Boar spermadhesin Awn-1 is a sperm surface-associated 14.7-kDa lectin and a major protein of porcine seminal plasma. Awn-1 binds to beta-galactosides and to porcine zona pellucida glycoproteins, suggesting that this protein might play a role in the primary binding of spermatozoa to the egg's external glycoprotein matrix. We have produced a collection of murine monoclonal antibodies against purified Awn-1. Five monoclonal antibodies recognized sequential antigenic determinants. All these epitopes were located at the C-terminal region of Awn-1 (residues 109-123) by competitive ELISA using overlapping synthetic peptides that cover the complete 133 amino acid sequence of the lectin. In a structural model of spermadhesin Awn-1, the polypeptide stretch 109-123 is fully solvent-exposed, providing a reasonable explanation for its high immunogenicity. In addition to epitope mapping, we have employed anti-Awn monoclonal antibodies for immunolocalization of the protein in the genital tract of inseminated sows. Clusters of Awn epitopes were occasionally found attached to the epithelium of the uterotubal junction and the adjacent lower isthmus. However, neither Awn-1 nor other seminal plasma proteins were found in the isthmic fluid collected 10-26 h after insemination. These results suggest that the whole amount of seminal plasma proteins are absorbed by the epithelium of the female genital tract, supporting the claim that removal of seminal plasma components from spermatozoa might be a major event in both in vitro and in vivo sperm capacitation.
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BOAR SPERMADHESIN Awn-1 : OLIGOSACCHARIDE AND ZONA PELLUCIDA BINDING CHARACTERISTICS
European journal of biochemistry, 1995Co-Authors: Zuzana Dostalova, Libia Sanz, Juan J. Calvete, Edda Töpfer-petersenAbstract:We have analyzed the oligosaccharide recognition ability of boar spermadhesin Awn-1 using biotinylated glycoproteins with defined carbohydrate chains as probes. Our results show that Awn-1 bound to proteins containing O-linked NeuAc alpha(2-3/6)-Gal beta(1-3)-GalNAc (PDC-109 and fetuin) with a Kd = 0.7 microM. Awn-1 also bound to NeuAc alpha(2-3/6)-Gal beta(1-4)-GlcNAc sequences in N-linked triantennary structures of fetuin, but not to the same oligosaccharide in the diantennary structures of IgG or fibrinogen. The absence of terminal sialic acid decreased fivefold the binding affinity. By competitive ELISA, peptides containing the N-linked oligosaccharide sequence inhibited the binding of the parent glycoprotein to immobilized Awn-1 5-45 times less effectively than those carrying O-linked NeuAc alpha(2-3/6)-Gal beta(1-3)-GalNAc structures. In addition, Awn-1 bound with a Kd = 0.3 microM to solubilized, biotinylated porcine zona pellucida glycoproteins. PDC-109 competed effectively with zona pellucida glycoproteins for Awn binding, whereas fetuin was a poor competitor. On the other hand, Awn epitopes were demonstrated on in vitro capacitated boar spermatozoa which were able to bind to, and penetrate, zona-encased oocytes. These data indicate that spermadhesin Awn-1 may play a role in pig fertilization as a sperm-associated lectin of broad specificity though preferential affinity for certain O-linked oligosaccharide structures of the oocyte's zona pellucida.
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Boar Spermadhesin Awn‐1
FEBS Journal, 1995Co-Authors: Zuzana Dostalova, Libia Sanz, Juan J. Calvete, Edda Töpfer-petersenAbstract:We have analyzed the oligosaccharide recognition ability of boar spermadhesin Awn-1 using biotinylated glycoproteins with defined carbohydrate chains as probes. Our results show that Awn-1 bound to proteins containing O-linked NeuAcα(2–3/6)-Galβ(1–3)-GalNAc (PDC-109 and fetuin) with a Kd=0.7 μM. Awn-1 also bound to NeuAcα(2–3/6)-Galβ(1–4)-GlcNAc sequences in N-linked triantennary structures of fetuin, but not to the same oligosaccharide in the diantennary structures of IgG or fibrinogen. The absence of terminal sialic acid decreased fivefold the binding affinity. By competitive ELISA, peptides containing the N-linked oligosaccharide sequence inhibited the binding of the parent glycoprotein to immobilized Awn-1 5 – 45 times less effectively than those carrying O-linked NeuAcα(2–3/6)-Galβ(1–3)-GalNAc structures. In addition, Awn-1 bound with a Kd=0.3 uM to solubilized, biotinylated porcine zona pellucida glycoproteins. PDC-109 competed effectively with zona pellucida glycoproteins for Awn binding, whereas fetuin was a poor competitor. On the other hand, Awn epitopes were demonstrated on in vitro capacitated boar spermatozoa which were able to bind to, and penetrate, zona-encased oocytes. These data indicate that spermadhesin Awn-1 may play a role in pig fertilization as a sperm-associated lectin of broad specificity though preferential affinity for certain O-linked oligosaccharide structures of the oocyte's zona pellucida.
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Immunohistochemical localization of spermadhesin Awn in the porcine male genital tract.
Cell and tissue research, 1995Co-Authors: Fred Sinowatz, Libia Sanz, Juan J. Calvete, Edda Töpfer-petersen, W. Amselgruber, Johanna PlendlAbstract:Boar spermadhesin (Awn) is a 14-kDa multifunctional protein, attached to the surface of the spermatozoa and involved in sperm capacitation and zona pellucida binding. The cellular origin of Awn was previously unknown. Moreover, the region of the male genital tract in which Awn becomes attached to the surface of spermatozoa was also uncertain. By using monospecific polyclonal antibodies against Awn, the immunohistochemical distribution pattern of Awn epitopes has been investigated in tissue sections of the porcine male genital tract. Our study has revealed that Awn is synthesized in the rete testis and in the epithelium of the seminal vesicles. The latter are also the major contributors of seminal plasma Awn. In addition, immunoblotting analysis has shown that Awn is present on epididymal spermatozoa. Our results indicate that the cellular origin of spermadhesins is species-specific. The attachment of Awn to epididymal spermatozoa is probably important in developing the capacity for fertilization.
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Characterization of Awn-1 glycosylated isoforms helps define the zona pellucida and serine proteinase inhibitor-binding region on boar spermadhesins
FEBS letters, 1993Co-Authors: Juan J. Calvete, Libia Sanz, Zuzana Dostalova, Edda Töpfer-petersenAbstract:Spermadhesin Awn-1 (14 kDa) belongs to a recently described family of boar sperm surface-associated proteins. Awn-1 is a multifunctional protein which possesses heparin-, serine proteinase inhibitor-, and zona pellucida glycoprotein-binding capability. Therefore it has been implicated in sperm capacitation and sperm-oocyte attachment. Here, we report the characterization of 22–25 kDa isoforms of Awn-1 isolated by heparin-affinity chromatography, which fail to bind to zona pellucida glycoproteins or serine proteinase inhibitors. Our results show that the structure of the high and low molecular mass Awn-1 forms differ in that the former is N-glycosylated at Asp50 and truncated at the C-terminus. The inability of the glycosylated Awn-1 molecules to bind ligands is due solely to the presence of the oligosaccharide moieties, however. This indicates that glycosylation of Awn-1 may modulate its ligand-binding capabilities. On the other hand, the effect of glycosylation on ligand-binding suggests that both the zona pellucida- and the serine proteinase inhibitor binding domain(s) may be located around the glycosylation point.
Juan J. Calvete - One of the best experts on this subject based on the ideXlab platform.
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Immunoelectronmicroscopic imaging of spermadhesin Awn epitopes on boar spermatozoa bound in vivo to the zona pellucida.
Reproduction fertility and development, 1998Co-Authors: Heriberto Rodriguez-martinez, A. Iborra, Paz Martínez, Juan J. CalveteAbstract:Spermadhesin Awn is a major protein of boar seminal plasma and a sperm surface-associated lectin. Awn binds to β-galactosides and to porcine zona pellucida glycoproteins, suggesting a role for this protein in primary gamete interaction. However, because capacitation induces remodelling of the sperm surface and Awn is peripherally bound to the plasma membrane, the present study sought to investigate whether Awn is present or absent in the subpopulation of spermatozoa that reaches the ovulated oocyte at the period of fertilization in vivo. Therefore, tubal tissues and oocytes from sows mated with a fertile boar were collected 6–8 h after ovulation. Tissues and oocyte–sperm complexes were fixed, immunolabelled with anti-Awn monoclonal antibodies, and examined by means of light and scanning electron microscopy. The results show that spermadhesin Awn is present in spermatozoa seen along the genital tract of the natural mated sow as well as on plasmalemmal remnants of spermatozoa bound to the zona pellucida in vivo.
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Monoclonal antibodies against boar sperm zona pellucida-binding protein Awn-1. Characterization of a continuous antigenic determinant and immunolocalization of Awn epitopes in inseminated sows.
Biology of reproduction, 1997Co-Authors: Juan J. Calvete, Libia Sanz, Edda Töpfer-petersen, Knut Adermann, Paz Martínez, Michael Ensslin, Jane Mburu, Antonio Iborra, Dagmar Waberski, K. F. WeitzeAbstract:Boar spermadhesin Awn-1 is a sperm surface-associated 14.7-kDa lectin and a major protein of porcine seminal plasma. Awn-1 binds to beta-galactosides and to porcine zona pellucida glycoproteins, suggesting that this protein might play a role in the primary binding of spermatozoa to the egg's external glycoprotein matrix. We have produced a collection of murine monoclonal antibodies against purified Awn-1. Five monoclonal antibodies recognized sequential antigenic determinants. All these epitopes were located at the C-terminal region of Awn-1 (residues 109-123) by competitive ELISA using overlapping synthetic peptides that cover the complete 133 amino acid sequence of the lectin. In a structural model of spermadhesin Awn-1, the polypeptide stretch 109-123 is fully solvent-exposed, providing a reasonable explanation for its high immunogenicity. In addition to epitope mapping, we have employed anti-Awn monoclonal antibodies for immunolocalization of the protein in the genital tract of inseminated sows. Clusters of Awn epitopes were occasionally found attached to the epithelium of the uterotubal junction and the adjacent lower isthmus. However, neither Awn-1 nor other seminal plasma proteins were found in the isthmic fluid collected 10-26 h after insemination. These results suggest that the whole amount of seminal plasma proteins are absorbed by the epithelium of the female genital tract, supporting the claim that removal of seminal plasma components from spermatozoa might be a major event in both in vitro and in vivo sperm capacitation.
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identification by affinity chromatography of boar sperm membrane associated proteins bound to immobilized porcine zona pellucida mapping of the phosphorylethanolamine binding region of spermadhesin Awn
Biological chemistry Hoppe-Seyler, 1995Co-Authors: M Ensslin, Libia Sanz, Juan J. Calvete, Hubert Thole, W D Sierralta, Knut Adermann, E TopferpetersenAbstract:Abstract We have identified boar sperm membrane components recovered by affinity chromatography on a porcine zona pellucida affinity column. The major zona pellucida-bound proteins were spermadhesins Awn and AQN-3, the heparin-binding protein pAIF, and a homolog of the mouse milk fat globule membrane protein. All these proteins are phospholipid-binding proteins peripherally associated with the plasma membrane. Our data suggest that coating proteins tightly bound to the external lipid bilayer may act as major zona pellucida-binding molecules. Using a synthetic peptide approach we show that the regions of spermadhesin Awn comprising residues 6-12 and 104-108 possess affinity for phosphorylethanolamine. These two amino acid sequences are in close proximity in the predicted structural model for Awn, and in opposite location to its carbohydrate-recognition domain. Taken together, our data provide further evidence for the possible involvement of members of the porcine spermadhesin protein family in gamete interaction and suggest a model for the ultrastructural disposition of functional domains of spermadhesin Awn bound to the sperm surface.
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BOAR SPERMADHESIN Awn-1 : OLIGOSACCHARIDE AND ZONA PELLUCIDA BINDING CHARACTERISTICS
European journal of biochemistry, 1995Co-Authors: Zuzana Dostalova, Libia Sanz, Juan J. Calvete, Edda Töpfer-petersenAbstract:We have analyzed the oligosaccharide recognition ability of boar spermadhesin Awn-1 using biotinylated glycoproteins with defined carbohydrate chains as probes. Our results show that Awn-1 bound to proteins containing O-linked NeuAc alpha(2-3/6)-Gal beta(1-3)-GalNAc (PDC-109 and fetuin) with a Kd = 0.7 microM. Awn-1 also bound to NeuAc alpha(2-3/6)-Gal beta(1-4)-GlcNAc sequences in N-linked triantennary structures of fetuin, but not to the same oligosaccharide in the diantennary structures of IgG or fibrinogen. The absence of terminal sialic acid decreased fivefold the binding affinity. By competitive ELISA, peptides containing the N-linked oligosaccharide sequence inhibited the binding of the parent glycoprotein to immobilized Awn-1 5-45 times less effectively than those carrying O-linked NeuAc alpha(2-3/6)-Gal beta(1-3)-GalNAc structures. In addition, Awn-1 bound with a Kd = 0.3 microM to solubilized, biotinylated porcine zona pellucida glycoproteins. PDC-109 competed effectively with zona pellucida glycoproteins for Awn binding, whereas fetuin was a poor competitor. On the other hand, Awn epitopes were demonstrated on in vitro capacitated boar spermatozoa which were able to bind to, and penetrate, zona-encased oocytes. These data indicate that spermadhesin Awn-1 may play a role in pig fertilization as a sperm-associated lectin of broad specificity though preferential affinity for certain O-linked oligosaccharide structures of the oocyte's zona pellucida.
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Boar Spermadhesin Awn‐1
FEBS Journal, 1995Co-Authors: Zuzana Dostalova, Libia Sanz, Juan J. Calvete, Edda Töpfer-petersenAbstract:We have analyzed the oligosaccharide recognition ability of boar spermadhesin Awn-1 using biotinylated glycoproteins with defined carbohydrate chains as probes. Our results show that Awn-1 bound to proteins containing O-linked NeuAcα(2–3/6)-Galβ(1–3)-GalNAc (PDC-109 and fetuin) with a Kd=0.7 μM. Awn-1 also bound to NeuAcα(2–3/6)-Galβ(1–4)-GlcNAc sequences in N-linked triantennary structures of fetuin, but not to the same oligosaccharide in the diantennary structures of IgG or fibrinogen. The absence of terminal sialic acid decreased fivefold the binding affinity. By competitive ELISA, peptides containing the N-linked oligosaccharide sequence inhibited the binding of the parent glycoprotein to immobilized Awn-1 5 – 45 times less effectively than those carrying O-linked NeuAcα(2–3/6)-Galβ(1–3)-GalNAc structures. In addition, Awn-1 bound with a Kd=0.3 uM to solubilized, biotinylated porcine zona pellucida glycoproteins. PDC-109 competed effectively with zona pellucida glycoproteins for Awn binding, whereas fetuin was a poor competitor. On the other hand, Awn epitopes were demonstrated on in vitro capacitated boar spermatozoa which were able to bind to, and penetrate, zona-encased oocytes. These data indicate that spermadhesin Awn-1 may play a role in pig fertilization as a sperm-associated lectin of broad specificity though preferential affinity for certain O-linked oligosaccharide structures of the oocyte's zona pellucida.
Libia Sanz - One of the best experts on this subject based on the ideXlab platform.
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Monoclonal antibodies against boar sperm zona pellucida-binding protein Awn-1. Characterization of a continuous antigenic determinant and immunolocalization of Awn epitopes in inseminated sows.
Biology of reproduction, 1997Co-Authors: Juan J. Calvete, Libia Sanz, Edda Töpfer-petersen, Knut Adermann, Paz Martínez, Michael Ensslin, Jane Mburu, Antonio Iborra, Dagmar Waberski, K. F. WeitzeAbstract:Boar spermadhesin Awn-1 is a sperm surface-associated 14.7-kDa lectin and a major protein of porcine seminal plasma. Awn-1 binds to beta-galactosides and to porcine zona pellucida glycoproteins, suggesting that this protein might play a role in the primary binding of spermatozoa to the egg's external glycoprotein matrix. We have produced a collection of murine monoclonal antibodies against purified Awn-1. Five monoclonal antibodies recognized sequential antigenic determinants. All these epitopes were located at the C-terminal region of Awn-1 (residues 109-123) by competitive ELISA using overlapping synthetic peptides that cover the complete 133 amino acid sequence of the lectin. In a structural model of spermadhesin Awn-1, the polypeptide stretch 109-123 is fully solvent-exposed, providing a reasonable explanation for its high immunogenicity. In addition to epitope mapping, we have employed anti-Awn monoclonal antibodies for immunolocalization of the protein in the genital tract of inseminated sows. Clusters of Awn epitopes were occasionally found attached to the epithelium of the uterotubal junction and the adjacent lower isthmus. However, neither Awn-1 nor other seminal plasma proteins were found in the isthmic fluid collected 10-26 h after insemination. These results suggest that the whole amount of seminal plasma proteins are absorbed by the epithelium of the female genital tract, supporting the claim that removal of seminal plasma components from spermatozoa might be a major event in both in vitro and in vivo sperm capacitation.
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identification by affinity chromatography of boar sperm membrane associated proteins bound to immobilized porcine zona pellucida mapping of the phosphorylethanolamine binding region of spermadhesin Awn
Biological chemistry Hoppe-Seyler, 1995Co-Authors: M Ensslin, Libia Sanz, Juan J. Calvete, Hubert Thole, W D Sierralta, Knut Adermann, E TopferpetersenAbstract:Abstract We have identified boar sperm membrane components recovered by affinity chromatography on a porcine zona pellucida affinity column. The major zona pellucida-bound proteins were spermadhesins Awn and AQN-3, the heparin-binding protein pAIF, and a homolog of the mouse milk fat globule membrane protein. All these proteins are phospholipid-binding proteins peripherally associated with the plasma membrane. Our data suggest that coating proteins tightly bound to the external lipid bilayer may act as major zona pellucida-binding molecules. Using a synthetic peptide approach we show that the regions of spermadhesin Awn comprising residues 6-12 and 104-108 possess affinity for phosphorylethanolamine. These two amino acid sequences are in close proximity in the predicted structural model for Awn, and in opposite location to its carbohydrate-recognition domain. Taken together, our data provide further evidence for the possible involvement of members of the porcine spermadhesin protein family in gamete interaction and suggest a model for the ultrastructural disposition of functional domains of spermadhesin Awn bound to the sperm surface.
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BOAR SPERMADHESIN Awn-1 : OLIGOSACCHARIDE AND ZONA PELLUCIDA BINDING CHARACTERISTICS
European journal of biochemistry, 1995Co-Authors: Zuzana Dostalova, Libia Sanz, Juan J. Calvete, Edda Töpfer-petersenAbstract:We have analyzed the oligosaccharide recognition ability of boar spermadhesin Awn-1 using biotinylated glycoproteins with defined carbohydrate chains as probes. Our results show that Awn-1 bound to proteins containing O-linked NeuAc alpha(2-3/6)-Gal beta(1-3)-GalNAc (PDC-109 and fetuin) with a Kd = 0.7 microM. Awn-1 also bound to NeuAc alpha(2-3/6)-Gal beta(1-4)-GlcNAc sequences in N-linked triantennary structures of fetuin, but not to the same oligosaccharide in the diantennary structures of IgG or fibrinogen. The absence of terminal sialic acid decreased fivefold the binding affinity. By competitive ELISA, peptides containing the N-linked oligosaccharide sequence inhibited the binding of the parent glycoprotein to immobilized Awn-1 5-45 times less effectively than those carrying O-linked NeuAc alpha(2-3/6)-Gal beta(1-3)-GalNAc structures. In addition, Awn-1 bound with a Kd = 0.3 microM to solubilized, biotinylated porcine zona pellucida glycoproteins. PDC-109 competed effectively with zona pellucida glycoproteins for Awn binding, whereas fetuin was a poor competitor. On the other hand, Awn epitopes were demonstrated on in vitro capacitated boar spermatozoa which were able to bind to, and penetrate, zona-encased oocytes. These data indicate that spermadhesin Awn-1 may play a role in pig fertilization as a sperm-associated lectin of broad specificity though preferential affinity for certain O-linked oligosaccharide structures of the oocyte's zona pellucida.
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Boar Spermadhesin Awn‐1
FEBS Journal, 1995Co-Authors: Zuzana Dostalova, Libia Sanz, Juan J. Calvete, Edda Töpfer-petersenAbstract:We have analyzed the oligosaccharide recognition ability of boar spermadhesin Awn-1 using biotinylated glycoproteins with defined carbohydrate chains as probes. Our results show that Awn-1 bound to proteins containing O-linked NeuAcα(2–3/6)-Galβ(1–3)-GalNAc (PDC-109 and fetuin) with a Kd=0.7 μM. Awn-1 also bound to NeuAcα(2–3/6)-Galβ(1–4)-GlcNAc sequences in N-linked triantennary structures of fetuin, but not to the same oligosaccharide in the diantennary structures of IgG or fibrinogen. The absence of terminal sialic acid decreased fivefold the binding affinity. By competitive ELISA, peptides containing the N-linked oligosaccharide sequence inhibited the binding of the parent glycoprotein to immobilized Awn-1 5 – 45 times less effectively than those carrying O-linked NeuAcα(2–3/6)-Galβ(1–3)-GalNAc structures. In addition, Awn-1 bound with a Kd=0.3 uM to solubilized, biotinylated porcine zona pellucida glycoproteins. PDC-109 competed effectively with zona pellucida glycoproteins for Awn binding, whereas fetuin was a poor competitor. On the other hand, Awn epitopes were demonstrated on in vitro capacitated boar spermatozoa which were able to bind to, and penetrate, zona-encased oocytes. These data indicate that spermadhesin Awn-1 may play a role in pig fertilization as a sperm-associated lectin of broad specificity though preferential affinity for certain O-linked oligosaccharide structures of the oocyte's zona pellucida.
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boar spermadhesin Awn 1
FEBS Journal, 1995Co-Authors: Zuzana Dostalova, Libia Sanz, Juan J. Calvete, Edda TopferpetersenAbstract:We have analyzed the oligosaccharide recognition ability of boar spermadhesin Awn-1 using biotinylated glycoproteins with defined carbohydrate chains as probes. Our results show that Awn-1 bound to proteins containing O-linked NeuAcα(2–3/6)-Galβ(1–3)-GalNAc (PDC-109 and fetuin) with a Kd=0.7 μM. Awn-1 also bound to NeuAcα(2–3/6)-Galβ(1–4)-GlcNAc sequences in N-linked triantennary structures of fetuin, but not to the same oligosaccharide in the diantennary structures of IgG or fibrinogen. The absence of terminal sialic acid decreased fivefold the binding affinity. By competitive ELISA, peptides containing the N-linked oligosaccharide sequence inhibited the binding of the parent glycoprotein to immobilized Awn-1 5 – 45 times less effectively than those carrying O-linked NeuAcα(2–3/6)-Galβ(1–3)-GalNAc structures. In addition, Awn-1 bound with a Kd=0.3 uM to solubilized, biotinylated porcine zona pellucida glycoproteins. PDC-109 competed effectively with zona pellucida glycoproteins for Awn binding, whereas fetuin was a poor competitor. On the other hand, Awn epitopes were demonstrated on in vitro capacitated boar spermatozoa which were able to bind to, and penetrate, zona-encased oocytes. These data indicate that spermadhesin Awn-1 may play a role in pig fertilization as a sperm-associated lectin of broad specificity though preferential affinity for certain O-linked oligosaccharide structures of the oocyte's zona pellucida.
Stefan Mertin - One of the best experts on this subject based on the ideXlab platform.
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piezoelectric and structural properties of c axis textured aluminium scandium nitride thin films up to high scandium content
Surface & Coatings Technology, 2018Co-Authors: Stefan Mertin, Oliver Rattunde, Sylvain Nicolay, Gabriel Christmann, Bernd Heinz, Marc Dubois, Paul MuraltAbstract:Abstract Partial substitution of aluminium by scandium in the wurtzite structure of aluminium nitride (AlN) leads to a large increase of the piezoelectric response by more than a factor of 2. Therefore, aluminium scandium nitride (ASN) thin films attracted much attention to improve piezoelectric MEMS devices such as RF filters, sensors, micro actuators and energy harvesting devices. In this work, process-microstructure-property relationships of ASN thin films containing up to 42% Sc were investigated. Like AlN thin films, ASN films are sputter deposited at 300–350°C with pulsed DC powered magnetrons. The influence of the process parameters on the film structure, the intrinsic stress and the piezoelectric response was investigated in order to achieve optimal piezoelectric coefficients up to high Sc concentrations. X-Ray diffraction (XRD) and transmission electron microscopy (TEM) were used to analyse the quality of c-axis texture. The films showed exclusively (002) texture with rocking-curve widths in the range of 1.3–2° (FHWM). The films were further analysed by scanning electron microscopy (SEM). The Sc content was determined by energy-dispersive X-ray spectroscopy (EDX). A good compositional homogeneity in the range of 0.5–1 at.% was achieved between border and centre of 200-mm wafers. So far, we obtained ASN films with transversal piezoelectric coefficients of up to e31,f = −2.77 C/m2, which is a factor 2.6 higher than in pure AlN thin films.
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enhanced piezoelectric properties of c axis textured aluminium scandium nitride thin films with high scandium content influence of intrinsic stress and sputtering parameters
Internaltional Ultrasonics Symposium, 2017Co-Authors: Stefan Mertin, Oliver Rattunde, Marc Alexandre Dubois, Gabriel Christmann, Bernd Heinz, Vladimir Pashchenko, Fazel Parsapour, Clemens Nyffeler, Cosmin S. Sandu, Paul MuraltAbstract:Aluminium scandium nitride (ASN) exhibits a largely enhanced piezoelectric response as compared to aluminium nitride (AlN), which makes it an upcoming piezoelectric material for use in next generation RF filters, sensors, actuators and energy harvesting devices. In this work, process-microstructure-property relationships of such sputtered ASN films containing up to 42 at% Sc were investigated. Hereby, the influence of the process parameters on the film structure, the intrinsic stress and the piezoelectric response were carefully investigated. A high piezoelectric response (e 31, f = −2.67 C/m2 and d 33, f = 10.3 pm/V) was measured for films with 42 at% and 34 at% Sc, respectively. The results are very promising towards industrial applications.
