The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Craig Vierra - One of the best experts on this subject based on the ideXlab platform.
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aciniform spidroin a constituent of egg case sacs and wrapping silk fibers from the black widow spider latrodectus hesperus
Journal of Biological Chemistry, 2007Co-Authors: Keshav Vasanthavada, Anne M F Moore, Coby La Mattina, Ryan Reza, Xiaoyi Hu, Patrick R Jones, Tiffany Tuton, Arnold M Falick, Craig VierraAbstract:Abstract Spiders produce high performance fibers with diverse mechanical properties and biological functions. Molecular and biochemical studies of spider egg case silk have revealed that the main constituent of the large diameter fiber contains the fibroin TuSp1. Here we demonstrate by SDS-PAGE and protein silver staining the presence of a distinct ∼300-kDa polypeptide that is found in solubilized egg case sacs. Combining matrix-assisted laser desorption ionization tandem time-of-flight mass spectrometry and reverse genetics, we have isolated a novel gene called AcSp1-like and demonstrate that its protein product is assembled into the small diameter fibers of egg case sacs and wrapping silks from the black widow spider, Latrodectus hesperus. BLAST searches of the NCBInr protein data base using the amino acid sequence of AcSp1-like revealed similarity to AcSp1, an inferred protein proposed to be a component of wrapping silk. However, the AcSp1-like protein was found to display more nonuniformity in its internal iterated repeat modules than the putative AcSp1 fibroin. Real time quantitative PCR analysis demonstrates that the AcSp1-like gene displays an aciniform gland-restricted pattern of expression. The amino acid composition of the Fibroins extracted from the luminal contents of the aciniform glands was remarkably similar to the predicted amino acid composition of the AcSp1-like protein, which supports the assertion that AcSp1-like protein represents the major constituent stored within the aciniform gland. Collectively, our findings provide the first direct molecular evidence for the involvement of the aciniform gland in the production of a common fibroin that is assembled into the small diameter threads of egg case and wrapping silk of cob weavers.
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egg case protein 1 a new class of silk proteins with fibroin like properties from the spider latrodectus hesperus
Journal of Biological Chemistry, 2005Co-Authors: Xiaoyi Hu, Anne M F Moore, Kristin Kohler, Patrick R Jones, David O Sparkman, Arnold M Falick, Craig VierraAbstract:Abstract Spiders produce multiple types of silk that exhibit diverse mechanical properties and biological functions. Most molecular studies of spider silk have focused on Fibroins from dragline silk and capture silk, two important silk types involved in the survival of the spider. In our studies we have focused on the characterization of egg case silk, a third silk fiber produced by the black widow spider, Latrodectus hesperus. Analysis of the physical structure of egg case silk using scanning electron microscopy demonstrates the presence of small and large diameter fibers. By using the strong protein denaturant 8 m guanidine hydrochloride to solubilize the fibers, we demonstrated by SDS-PAGE and protein silver staining that an abundant component of egg case silk is a 100-kDa protein doublet. Combining matrix-assisted laser desorption ionization tandem time-of-flight mass spectrometry and reverse genetics, we have isolated a novel gene called ecp-1, which encodes for one of the protein components of the 100-kDa species. BLAST searches of the NCBInr protein data base using the primary sequence of ECP-1 revealed similarity to Fibroins from spiders and silkworms, which mapped to two distinct regions within the ECP-1. These regions contained the conserved repetitive fibroin motifs poly(Ala) and poly(Gly-Ala), but surprisingly, no larger ensemble repeats could be identified within the primary sequence of ECP-1. Consistent with silk gland-restricted patterns of expression for Fibroins, ECP-1 was demonstrated to be predominantly produced in the tubuliform gland, with lower levels detected in the major and minor ampullate glands. ECP-1 monomeric units were also shown to assemble into higher aggregate structures through the formation of disulfide bonds via a unique cysteine-rich N-terminal region. Collectively, our findings provide new insight into the components of egg case silk and identify a new class of silk proteins with distinctive molecular features relative to traditional members of the spider silk gene family.
Xiaoyi Hu - One of the best experts on this subject based on the ideXlab platform.
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aciniform spidroin a constituent of egg case sacs and wrapping silk fibers from the black widow spider latrodectus hesperus
Journal of Biological Chemistry, 2007Co-Authors: Keshav Vasanthavada, Anne M F Moore, Coby La Mattina, Ryan Reza, Xiaoyi Hu, Patrick R Jones, Tiffany Tuton, Arnold M Falick, Craig VierraAbstract:Abstract Spiders produce high performance fibers with diverse mechanical properties and biological functions. Molecular and biochemical studies of spider egg case silk have revealed that the main constituent of the large diameter fiber contains the fibroin TuSp1. Here we demonstrate by SDS-PAGE and protein silver staining the presence of a distinct ∼300-kDa polypeptide that is found in solubilized egg case sacs. Combining matrix-assisted laser desorption ionization tandem time-of-flight mass spectrometry and reverse genetics, we have isolated a novel gene called AcSp1-like and demonstrate that its protein product is assembled into the small diameter fibers of egg case sacs and wrapping silks from the black widow spider, Latrodectus hesperus. BLAST searches of the NCBInr protein data base using the amino acid sequence of AcSp1-like revealed similarity to AcSp1, an inferred protein proposed to be a component of wrapping silk. However, the AcSp1-like protein was found to display more nonuniformity in its internal iterated repeat modules than the putative AcSp1 fibroin. Real time quantitative PCR analysis demonstrates that the AcSp1-like gene displays an aciniform gland-restricted pattern of expression. The amino acid composition of the Fibroins extracted from the luminal contents of the aciniform glands was remarkably similar to the predicted amino acid composition of the AcSp1-like protein, which supports the assertion that AcSp1-like protein represents the major constituent stored within the aciniform gland. Collectively, our findings provide the first direct molecular evidence for the involvement of the aciniform gland in the production of a common fibroin that is assembled into the small diameter threads of egg case and wrapping silk of cob weavers.
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egg case protein 1 a new class of silk proteins with fibroin like properties from the spider latrodectus hesperus
Journal of Biological Chemistry, 2005Co-Authors: Xiaoyi Hu, Anne M F Moore, Kristin Kohler, Patrick R Jones, David O Sparkman, Arnold M Falick, Craig VierraAbstract:Abstract Spiders produce multiple types of silk that exhibit diverse mechanical properties and biological functions. Most molecular studies of spider silk have focused on Fibroins from dragline silk and capture silk, two important silk types involved in the survival of the spider. In our studies we have focused on the characterization of egg case silk, a third silk fiber produced by the black widow spider, Latrodectus hesperus. Analysis of the physical structure of egg case silk using scanning electron microscopy demonstrates the presence of small and large diameter fibers. By using the strong protein denaturant 8 m guanidine hydrochloride to solubilize the fibers, we demonstrated by SDS-PAGE and protein silver staining that an abundant component of egg case silk is a 100-kDa protein doublet. Combining matrix-assisted laser desorption ionization tandem time-of-flight mass spectrometry and reverse genetics, we have isolated a novel gene called ecp-1, which encodes for one of the protein components of the 100-kDa species. BLAST searches of the NCBInr protein data base using the primary sequence of ECP-1 revealed similarity to Fibroins from spiders and silkworms, which mapped to two distinct regions within the ECP-1. These regions contained the conserved repetitive fibroin motifs poly(Ala) and poly(Gly-Ala), but surprisingly, no larger ensemble repeats could be identified within the primary sequence of ECP-1. Consistent with silk gland-restricted patterns of expression for Fibroins, ECP-1 was demonstrated to be predominantly produced in the tubuliform gland, with lower levels detected in the major and minor ampullate glands. ECP-1 monomeric units were also shown to assemble into higher aggregate structures through the formation of disulfide bonds via a unique cysteine-rich N-terminal region. Collectively, our findings provide new insight into the components of egg case silk and identify a new class of silk proteins with distinctive molecular features relative to traditional members of the spider silk gene family.
Masahisa Wada - One of the best experts on this subject based on the ideXlab platform.
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cellulose silk fibroin hydrogels prepared in a lithium bromide aqueous solution
Cellulose, 2017Co-Authors: Yeo Jeong Yang, Hyun Ju Oh, Satoshi Kimura, Masahisa WadaAbstract:Here, we present a new process for the preparation of cellulose–silk fibroin hydrogels using a concentrated lithium bromide (LiBr) aqueous solution. After mixing, the solutions of cellulose and silk fibroin that had each been dissolved separately in aqueous LiBr, the cellulose forms a gel as the solution cools to approximately 70°C, and silk fibroin is regenerated via treatment in methanol. Three grades of cellulose–silk fibroin hydrogels are prepared by controlling the amounts of cellulose and silk fibroin. The gels have highly porous, three-dimensional networks composed of long, interconnected fibrils. Through X-ray diffraction and ATR-FTIR analysis we show that the dissolution-regeneration of cellulose and silk fibroin induces a structural change in the crystal structure of cellulose II and silk II. While the porosity and swelling ratio of cellulose–silk fibroin gels is significantly reduced with the increased silk fibroin content, all the gels show high water uptake. The enzymatic degradation rates of cellulose–silk fibroin gels obviously reflect differences in the silk fibroin content, and cell adhesion and growth on cellulose–silk fibroin gels is enhanced with increased silk fibroin content. These cellulose–silk fibroin gels could provide novel properties that would be useful for biomaterial matrix applications.
Frantisek Sehnal - One of the best experts on this subject based on the ideXlab platform.
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DOI 10.1007/s00239-009-9234-5 Conservation of Silk Genes in Trichoptera and Lepidoptera
2013Co-Authors: Toshiki Tamura Æ Frantisˇek Sehnal, Naoyuki Yonemura, Toshiki Tamura, Kazuei Mita, Frantisek SehnalAbstract:Ó The Author(s) 2009. This article is published with open access at Springerlink.com Abstract Larvae of the sister orders Trichoptera and Lepidoptera are characterized by silk secretion from a pair of labial glands. In both orders the silk filament consists of heavy (H)- and light (L)-chain Fibroins and in Lepidoptera it also includes a P25 glycoprotein. The L-fibroin and H-fibroin genes of Rhyacophila obliterata and Hydropsyche angustipennis caddisflies have exon/intron structuring (seven exons in L-fibroin and two in H-fibroin) similar to that in their counterparts in Lepidoptera. Fibroin cDNAs are also known in Limnephilus decipiens, representing the third caddisfly suborder. Amino acid sequences of deduced L-fibroin proteins and of the terminal H-fibroin regions are about 50 % identical among the three caddisfly species but their similarity to lepidopteran Fibroins is \25%. Positions of some residues are conserved, including cysteines that were shown to link the L-fibroin and H-fibroin by a disulfide bridge in Lepidoptera. The long internal part of H-Fibroins is composed of short motifs arranged in speciesspecific repeats. They are extremely uniform in R. obliterata. Motifs (SX)n, GGX, and GPGXX occur in both Trichoptera and Lepidoptera. The trichopteran H-Fibroins further contain charged amphiphilic motifs but lack the strings of alanines or alanine-glycine dipeptides that are typical lepidopteran motifs. On the other hand, sequences composed of a motif similar to ERIVAPTVITR surrounded by the (SX)4-6 strings and modifications of th
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Molecular Evolution of Lepidopteran Silk Proteins: Insights from the Ghost Moth, Hepialus californicus
2013Co-Authors: Frantisek Sehnal, Kazuei Mita, Cheryl Y Hayashi, Matthew A. Collin, K. Mita, Lepidoptera Trichoptera Silk FibroinAbstract:Ó The Author(s) 2010. This article is published with open access at Springerlink.com Abstract Silk production has independently evolved in numerous arthropod lineages, such as Lepidoptera, the moths and butterflies. Lepidopteran larvae (caterpillars) synthesize silk proteins in modified salivary glands and spin silk fibers into protective tunnels, escape lines, and pupation cocoons. Molecular sequence data for these proteins are necessary to determine critical features of their function and evolution. To this end, we constructed an expression library from the silk glands of the ghost moth, Hepialus californicus, and characterized light chain fibroin and heavy chain fibroin gene transcripts. The predicted H. californicus silk Fibroins share many elements with other lepidopteran and trichopteran Fibroins, such as conserved placements of cysteine, aromatic, and polar amino acid residues. Further comparative analyses were performed to determine site-specific signatures of selection and to assess whether fibroin genes are informative as phylogenetic markers. We found that purifying selection has constrained mutation within the Fibroins and that light chain fibroin is a promising molecular marker. Thus, by characterizing the H. californicus Fibroins, we identified key functional amino acids and gained insight into the evolutionary processes that have shaped these adaptive molecules
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Functional Conservation and Structural Diversification of Silk Sericins in Two Moth Species
2013Co-Authors: Michal Zurovec, Barbara Kludkiewicz, Robert Fedic, Jitka Sulitkova, Vaclav Mach, Lucie Kucerova, Frantisek SehnalAbstract:Sericins are hydrophilic structural proteins produced by caterpillars in the middle section of silk glands and layered over fibroin proteins secreted in the posterior section. In the process of spinning, Fibroins form strong solid filaments, while sericins seal the pair of filaments into a single fiber and glue the fiber into a cocoon. Galleria mellonella and the previously examined Bombyx mori harbor three sericin genes that encode proteins containing long repetitive regions. Galleria sericin genes are similar to each other and the protein repeats are built from short and extremely serine-rich motifs, while Bombyx sericin genes are diversified and encode proteins with long and complex repeats. Developmental changes in sericin properties are controlled at the level of gene expression and splicing. In Galleria, MG-1 sericin is produced throughout larval life until the wandering stage, while the production of MG-2 and MG-3 reaches a peak during cocoon spinning
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Molecular Evolution of Lepidopteran Silk Proteins: Insights from the Ghost Moth, Hepialus californicus
Journal of Molecular Evolution, 2010Co-Authors: Matthew A. Collin, Frantisek Sehnal, Kazuei Mita, Cheryl Y HayashiAbstract:Silk production has independently evolved in numerous arthropod lineages, such as Lepidoptera, the moths and butterflies. Lepidopteran larvae (caterpillars) synthesize silk proteins in modified salivary glands and spin silk fibers into protective tunnels, escape lines, and pupation cocoons. Molecular sequence data for these proteins are necessary to determine critical features of their function and evolution. To this end, we constructed an expression library from the silk glands of the ghost moth, Hepialus californicus , and characterized light chain fibroin and heavy chain fibroin gene transcripts. The predicted H. californicus silk Fibroins share many elements with other lepidopteran and trichopteran Fibroins, such as conserved placements of cysteine, aromatic, and polar amino acid residues. Further comparative analyses were performed to determine site-specific signatures of selection and to assess whether fibroin genes are informative as phylogenetic markers. We found that purifying selection has constrained mutation within the Fibroins and that light chain fibroin is a promising molecular marker. Thus, by characterizing the H. californicus Fibroins, we identified key functional amino acids and gained insight into the evolutionary processes that have shaped these adaptive molecules.
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Conservation of Silk Genes in Trichoptera and Lepidoptera
Journal of Molecular Evolution, 2009Co-Authors: Naoyuki Yonemura, Toshiki Tamura, Kazuei Mita, Frantisek SehnalAbstract:Larvae of the sister orders Trichoptera and Lepidoptera are characterized by silk secretion from a pair of labial glands. In both orders the silk filament consists of heavy (H)- and light (L)-chain Fibroins and in Lepidoptera it also includes a P25 glycoprotein. The L-fibroin and H-fibroin genes of Rhyacophila obliterata and Hydropsyche angustipennis caddisflies have exon/intron structuring (seven exons in L-fibroin and two in H-fibroin ) similar to that in their counterparts in Lepidoptera. Fibroin cDNAs are also known in Limnephilus decipiens , representing the third caddisfly suborder. Amino acid sequences of deduced L-fibroin proteins and of the terminal H-fibroin regions are about 50% identical among the three caddisfly species but their similarity to lepidopteran Fibroins is
Anne M F Moore - One of the best experts on this subject based on the ideXlab platform.
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aciniform spidroin a constituent of egg case sacs and wrapping silk fibers from the black widow spider latrodectus hesperus
Journal of Biological Chemistry, 2007Co-Authors: Keshav Vasanthavada, Anne M F Moore, Coby La Mattina, Ryan Reza, Xiaoyi Hu, Patrick R Jones, Tiffany Tuton, Arnold M Falick, Craig VierraAbstract:Abstract Spiders produce high performance fibers with diverse mechanical properties and biological functions. Molecular and biochemical studies of spider egg case silk have revealed that the main constituent of the large diameter fiber contains the fibroin TuSp1. Here we demonstrate by SDS-PAGE and protein silver staining the presence of a distinct ∼300-kDa polypeptide that is found in solubilized egg case sacs. Combining matrix-assisted laser desorption ionization tandem time-of-flight mass spectrometry and reverse genetics, we have isolated a novel gene called AcSp1-like and demonstrate that its protein product is assembled into the small diameter fibers of egg case sacs and wrapping silks from the black widow spider, Latrodectus hesperus. BLAST searches of the NCBInr protein data base using the amino acid sequence of AcSp1-like revealed similarity to AcSp1, an inferred protein proposed to be a component of wrapping silk. However, the AcSp1-like protein was found to display more nonuniformity in its internal iterated repeat modules than the putative AcSp1 fibroin. Real time quantitative PCR analysis demonstrates that the AcSp1-like gene displays an aciniform gland-restricted pattern of expression. The amino acid composition of the Fibroins extracted from the luminal contents of the aciniform glands was remarkably similar to the predicted amino acid composition of the AcSp1-like protein, which supports the assertion that AcSp1-like protein represents the major constituent stored within the aciniform gland. Collectively, our findings provide the first direct molecular evidence for the involvement of the aciniform gland in the production of a common fibroin that is assembled into the small diameter threads of egg case and wrapping silk of cob weavers.
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egg case protein 1 a new class of silk proteins with fibroin like properties from the spider latrodectus hesperus
Journal of Biological Chemistry, 2005Co-Authors: Xiaoyi Hu, Anne M F Moore, Kristin Kohler, Patrick R Jones, David O Sparkman, Arnold M Falick, Craig VierraAbstract:Abstract Spiders produce multiple types of silk that exhibit diverse mechanical properties and biological functions. Most molecular studies of spider silk have focused on Fibroins from dragline silk and capture silk, two important silk types involved in the survival of the spider. In our studies we have focused on the characterization of egg case silk, a third silk fiber produced by the black widow spider, Latrodectus hesperus. Analysis of the physical structure of egg case silk using scanning electron microscopy demonstrates the presence of small and large diameter fibers. By using the strong protein denaturant 8 m guanidine hydrochloride to solubilize the fibers, we demonstrated by SDS-PAGE and protein silver staining that an abundant component of egg case silk is a 100-kDa protein doublet. Combining matrix-assisted laser desorption ionization tandem time-of-flight mass spectrometry and reverse genetics, we have isolated a novel gene called ecp-1, which encodes for one of the protein components of the 100-kDa species. BLAST searches of the NCBInr protein data base using the primary sequence of ECP-1 revealed similarity to Fibroins from spiders and silkworms, which mapped to two distinct regions within the ECP-1. These regions contained the conserved repetitive fibroin motifs poly(Ala) and poly(Gly-Ala), but surprisingly, no larger ensemble repeats could be identified within the primary sequence of ECP-1. Consistent with silk gland-restricted patterns of expression for Fibroins, ECP-1 was demonstrated to be predominantly produced in the tubuliform gland, with lower levels detected in the major and minor ampullate glands. ECP-1 monomeric units were also shown to assemble into higher aggregate structures through the formation of disulfide bonds via a unique cysteine-rich N-terminal region. Collectively, our findings provide new insight into the components of egg case silk and identify a new class of silk proteins with distinctive molecular features relative to traditional members of the spider silk gene family.