Shell matrices of Recent rhynchonelliform brachiopods: microstructures and glycosylation studies

2007 ◽  
Vol 98 (3-4) ◽  
pp. 415-424 ◽  
Author(s):  
Danièle Gaspard ◽  
Frédéric Marin ◽  
Nathalie Guichard ◽  
Sylvain Morel ◽  
Gérard Alcaraz ◽  
...  
Keyword(s):  
Organic Matrix ◽  
Crystal Nucleation ◽  
Low Molecular Weight ◽  
Post Translational Modifications ◽  
Shell Matrix ◽  
Positive Smear ◽  
Pas Staining ◽  
Polysaccharide Composition ◽  
Calcification Process ◽  
Outer Mantle Epithelium

ABSTRACTLike most metazoan biomineralisations, the brachiopod shell is the end product of a biologically controlled calcification process. The main agent of the control is the extracellular matrix, which is secreted by the outer mantle epithelium. This matrix mediates the calcification process by allowing crystal nucleation and elongation in specific orientations and finally, by stopping crystal growth. The proteinaceous moiety of brachiopod shell matrices has been extensively studied. Less known are the post-translational modifications that occur in these matrices, in particular glycosylations. In this comparison of five species of Recent articulated brachiopods, the ratio of soluble to insoluble organic matrix varies between the species. Polydisperse macromolecular materials occur in each of these species with discrete proteins of 50 kDa in Notosaria nigricans, Calloria inconspicua and Neothyris lenticularis, 37 kDa in Terebratulina retusa and Gryphus vitreus and 20–25 kDa in N. nigricans. Protein mixtures from all five species respond differently to anionic stains (Stains-All and Alcian Blue). PAS staining results in a positive smear in C. inconspicua and T. retusa and highlights low molecular weight glycoproteins in C. inconspicua. The polysaccharide composition of the soluble matrix of T. retusa is different from the others due to high proportions of arabinose and low proportions of fucose. In all cases, polysaccharide composition of the insoluble matrix is dominated by glucose and glucosamine. Insoluble matrices have more glucose and xylose and less galactosamine and glucosamine than the corresponding soluble matrix. Relatively high amounts of glucosamine may suggest the presence of chitin in the shell matrix of rhynchonelliform brachiopods.

Normal Mature Human Enamel Protein

1979 ◽  
Vol 58 (2_suppl) ◽  
pp. 986-987 ◽  
Author(s):  
A. Belcourt
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Gel Electrophoresis ◽  
Protein Concentration ◽  
Polyacrylamide Gel Electrophoresis ◽  
Organic Matrix ◽  
Low Molecular Weight ◽  
Human Enamel ◽  
Weak Density ◽  
Enamel Protein

Pure enamel was prepared using an original microdissection technic. Protein concentration was 375 μg per gram of enamel. Polyacrylamide gel electrophoresis showed a single fast-migrating zone containing a thin double band. Ultracentrifugation studies suggested that the proteins were of low molecular weight or of weak density. Absorption spectra showed a strong absorbance at 260nm. Amino acid analyses yielded a composition of 25% Gly, 13.5% Glu, 11% Ser, 11% Pro, 2% Cys and 2% Hyp. A glucidic content of 15% was estimated and glucose, galactose, mannose and fucose were identified. The organic matrix of enamel seemed to be constituted of two major glycoproteins probably fibrous but different from keratin.

The Possible Calcification Mechanisms in some Reptilian Egg-shells

1959 ◽  
Vol s3-100 (52) ◽  
pp. 529-538
Author(s):  
K. SIMKISS ◽  
C. TYLER
Keyword(s):  
Toluidine Blue ◽  
Organic Matrix ◽  
Acid Mucopolysaccharide ◽  
Amino Group ◽  
Carboxylate Group ◽  
Shell Matrix ◽  
The Matrix ◽  
Egg Shells ◽  
Egg Shell ◽  
Comparison Of The Results

Studies have been made of the organic matrix of certain reptilian egg-shells. The interaction between egg-shell-matrix and various metal ions has been considered by noting the effect of these ions on the staining of the matrix by toluidine blue. A comparison of the results with those for the hen indicates that the chelating mechanism in the Chelonia is similar to that in the hen, but that that in the Crocodilia is different. It is suggested that in the Crocodilia the acid mucopolysaccharide of the matrix is embedded in, but not combined with, the protein and that its chelating mechanism is carboxylate group to carboxylate group, while in the hen and Chelonia, the acid mucopolysaccharide is combined with the protein and that its chelating mechanism is carboxylate group to amino group.

scholarly journals Characterization of the main steps in first shell formation in Mytilus galloprovincialis : possible role of tyrosinase

2019 ◽  
Vol 286 (1916) ◽  
pp. 20192043 ◽  
Author(s):  
A. Miglioli ◽  
R. Dumollard ◽  
T. Balbi ◽  
L. Besnardeau ◽  
L. Canesi
Keyword(s):  
Time Course ◽  
Mytilus Galloprovincialis ◽  
Enzyme Inhibitor ◽  
Organic Matrix ◽  
Mrna Levels ◽  
Shell Formation ◽  
Larval Stages ◽  
Matrix Deposition ◽  
Shell Matrix

Bivalve biomineralization is a highly complex and organized process, involving several molecular components identified in adults and larval stages. However, information is still scarce on the ontogeny of the organic matrix before calcification occurs. In this work, first shell formation was investigated in the mussel Mytilus galloprovincialis . The time course of organic matrix and CaCO 3 deposition were followed at close times post fertilization (24, 26, 29, 32, 48 h) by calcofluor and calcein staining, respectively. Both components showed an exponential trend in growth, with a delay between organic matrix and CaCO 3 deposition. mRNA levels of genes involved in matrix deposition (chitin synthase; tyrosinase- TYR) and calcification (carbonic anhydrase; extrapallial protein) were quantified by qPCR at 24 and 48 hours post fertilization (hpf) with respect to eggs. All transcripts were upregulated across early development, with TYR showing highest mRNA levels from 24 hpf. TYR transcripts were closely associated with matrix deposition as shown by in situ hybridization. The involvement of tyrosinase activity was supported by data obtained with the enzyme inhibitor N-phenylthiourea. Our results underline the pivotal role of shell matrix in driving first CaCO 3 deposition and the importance of tyrosinase in the formation of the first shell in M. galloprovincialis .

Genetic Coding in Biomineralization of Microlaminate Composites

1992 ◽  
Vol 292 ◽  
Author(s):  
Daniel E. Morse ◽  
Marios A. Cariolou ◽  
Galen D. Stucky ◽  
Charlotite M. Zaremba ◽  
Paul K. Hansma
Keyword(s):  
Organic Matrix ◽  
Nucleation And Growth ◽  
Direct Crystallization ◽  
Basic Principles ◽  
Shell Matrix ◽  
Additional Protein ◽  
Flexible Deformation ◽  
Abalone Shell ◽  
Crystalline Domains ◽  
Present Understanding

AbstractBiomineralization is precisely controlled by complex templating relationships ultimately encoded in the genes. In the formation of the molluscan shell, polyanionic pleated sheet proteins serve as templates for the nucleation and epitaxial growth of calcium carbonate crystalline domains to yield microlaminate composites of exceptional strength and crystal ordering. The strength and fracture-resistance of these composites far exceed those of the minerals themselves, as a result of both the capacity for flexible deformation of the organic matrix layers and the retardation of crack propagation at each mineral-organic interface. The basic principles controlling low temperature biosynthesis of these materials thus are of both fundamental and applied importance. The abalone shell consists of microlaminates with a remarkable regularity of lamina thickness (ca. 0.5 micron), the formation of which defies present understanding. We have found that shells of abalone larvae formed prior to metamorphosis contain only aragonite, whereas the adult shell made after metamorphosis contains both aragonite and calcite. This transition is accompanied by a switch in genetic expression of the template proteins, suggesting that the premetamorphic protein may serve as a template for aragonite nucleation and growth, while template proteins synthesized after metamorphosis may direct crystallization of calcite. These analyses are based on improvements we recently reported for the detection and purification of proteins from the demineralized shell matrix. Genetic cloning experiments now in progress are aimed at discovering additional protein sequences responsible for the programmed control of crystal phase termination, since it is the termination and reinitiation of mineralization that is responsible for the regularity of highly ordered microlaminates produced in nature.

Calcium Mineral-Peptide Interactions

1989 ◽  
Vol 174 ◽  
Author(s):  
A. P. Wheeler ◽  
C. Steven Sikes
Keyword(s):  
Solid Phase ◽  
Binding Capacity ◽  
Calcium Phosphates ◽  
Organic Matrix ◽  
Crystal Nucleation ◽  
Crystal Surfaces ◽  
Major Class ◽  
Peptide Interactions ◽  
Carbonate Shell ◽  
The Matrix

AbstractPeptides have been synthesized by solid phase methods with structures which are in part based on experimentally-determined features of a major class of organic matrix phosphoproteins isolated from the calcium carbonate shell of the oyster. The matrix structures mimicked in the synthetic peptides included runs of aspartic acid (Asp), which were contrasted with peptides having other deployments of Asp with serine (Ser) and glycine (Gly). In addition, peptide-Ser was phosphorylated (PSer) and the hydrophobic carboxyterminus of natural matrix was mimicked using polyalanine tails. The interaction of the various peptides with CaCO3 as well as calcium phosphates was determined using a variety of crystallization assays and studies of adsorption of radio-labelled peptides to crystal surfaces.In general, peptides that include runs of Asp regulate crystal nucleation and growth more effectively than those which contain (Asp-X)n or (Asp-X-Y)n sequences with X and Y being either Gly or Ser. Further, CaCO3 crystals have a much higher binding capacity for polyAsp than for peptides with other deployments of Asp. Phosphorylation increases the regulatory activity and the crystal capacities of Asp/Ser - containing peptides. PolyAsp peptides having terminal PSer's are especially effective as regulators of CaCO3 nucleation and the conversion of amorphous calcium phosphate to apatite. The activity of Asp15 molecules in CaCO3 nucleation assays is markedly increased by the addition of polyalanine tails.

scholarly journals Enamel Proteases Reduce Amelogenin-Apatite Binding

2008 ◽  
Vol 87 (12) ◽  
pp. 1133-1137 ◽  
Author(s):  
Z. Sun ◽  
D. Fan ◽  
Y. Fan ◽  
C. Du ◽  
J. Moradian-Oldak
Keyword(s):  
Protein Adsorption ◽  
Binding Affinity ◽  
Organic Matrix ◽  
Cleavage Product ◽  
Langmuir Model ◽  
Crystal Nucleation ◽  
Matrix Degradation ◽  
Kallikrein 4 ◽  
C And N ◽  
Mineral Interaction

Organic matrix degradation and crystal maturation are extracellular events that occur simultaneously during enamel biomineralization. We hypothesized that enamel proteases control amelogenin-mineral interaction, which, in turn can affect crystal nucleation, organization, and growth. We used a recombinant amelogenin (rP172), a homolog of its major cleavage product (rP148), and a native amelogenin lacking both N- and C-termini (13k). We compared apatite binding affinity between amelogenins and their digest products during proteolysis. We further compared binding affinity among the 3 amelogenins using a Langmuir model for protein adsorption. Amelogenin-apatite binding affinity was progressively reduced with the proteolysis at the C- and N- termini by recombinant pig MMP-20 (rpMMP20) and recombinant human kallikrein-4 (rhKLK4), respectively. The binding affinity of amelogenin to apatite was found to be in the descending order of rP172, rP148, and 13k. Analysis of our data suggests that, before its complete degradation during enamel maturation, stepwise processing of amelogenin by MMP-20 and then KLK4 reduces amelogenin-apatite interaction.

Shell regeneration in Helix: shell matrix composition and crystal formation

1969 ◽  
Vol 47 (6) ◽  
pp. 1107-1111 ◽  
Author(s):  
A. S. M. Saleuddin ◽  
Wilson Chan
Keyword(s):  
Chemical Nature ◽  
Early Stage ◽  
Organic Matrix ◽  
Matrix Composition ◽  
Crystal Formation ◽  
Shell Matrix ◽  
Nucleation Sites ◽  
Small Crystals ◽  
Short Period ◽  
Shell Regeneration

The chemical nature of the electron-dense areas appearing on the organic matrix during the early stage of shell regeneration in Helix has been ascertained. These areas of 500–5000 Å are made up mainly of acid mucopolysaccharides as detected by thorium staining. When treated by 1% phosphotungstic acid (PTA) for a short period, these electron-dense areas took up the stain, suggesting the presence of mucoprotein and glycoproteins, and are probably the nucleation sites for calcification because small crystals of CaCO3 appear with them. The small crystals join to form larger ones. Crystals grow presumably by dendritic growth, and eventually form a calcified layer. Electron diffraction studies on these crystals show the presence of aragonite (type present in the normal shell) and calcite.

scholarly journals The ‘Shellome’ of the Crocus Clam Tridacna crocea Emphasizes Essential Components of Mollusk Shell Biomineralization

2021 ◽  
Vol 12 ◽  
Author(s):  
Takeshi Takeuchi ◽  
Manabu Fujie ◽  
Ryo Koyanagi ◽  
Laurent Plasseraud ◽  
Isabelle Ziegler-Devin ◽  
...  
Keyword(s):  
Organic Matrix ◽  
The Other ◽  
Matrix Proteins ◽  
Shell Formation ◽  
Molluscan Shell ◽  
Shell Matrix ◽  
Essential Components ◽  
Shell Matrix Proteins ◽  
Shell Organic Matrix ◽  
Tridacna Crocea

Molluscan shells are among the most fascinating research objects because of their diverse morphologies and textures. The formation of these delicate biomineralized structures is a matrix-mediated process. A question that arises is what are the essential components required to build these exoskeletons. In order to understand the molecular mechanisms of molluscan shell formation, it is crucial to identify organic macromolecules in different shells from diverse taxa. In the case of bivalves, however, taxon sampling in previous shell proteomics studies are focused predominantly on representatives of the class Pteriomorphia such as pearl oysters, edible oysters and mussels. In this study, we have characterized the shell organic matrix from the crocus clam, Tridacna crocea, (Heterodonta) using various biochemical techniques, including SDS-PAGE, FT-IR, monosaccharide analysis, and enzyme-linked lectin assay (ELLA). Furthermore, we have identified a number of shell matrix proteins (SMPs) using a comprehensive proteomics approach combined to RNA-seq. The biochemical studies confirmed the presence of proteins, polysaccharides, and sulfates in the T. crocea shell organic matrix. Proteomics analysis revealed that the majority of the T. crocea SMPs are novel and dissimilar to known SMPs identified from the other bivalve species. Meanwhile, the SMP repertoire of the crocus clam also includes proteins with conserved functional domains such as chitin-binding domain, VWA domain, and protease inhibitor domain. We also identified BMSP (Blue Mussel Shell Protein, originally reported from Mytilus), which is widely distributed among molluscan shell matrix proteins. Tridacna SMPs also include low-complexity regions (LCRs) that are absent in the other molluscan genomes, indicating that these genes may have evolved in specific lineage. These results highlight the diversity of the organic molecules – in particular proteins – that are essential for molluscan shell formation.

Trends in the Analysis of Biopharmaceuticals by HPLC

2020 ◽  
Vol 16 (1) ◽  
pp. 52-58
Author(s):  
Angela Tartaglia ◽  
Marcello Locatelli ◽  
Victoria Samanidou
Keyword(s):  
Living Organism ◽  
Point Of View ◽  
European Medicines Agency ◽  
Low Molecular Weight ◽  
Immune Disorders ◽  
Biological Drugs ◽  
Post Translational Modifications ◽  
Regulatory Guidelines ◽  
Structural Point

Background: Biopharmaceuticals are biological drugs consisting of a complex compound that can be produced by a living organism or derive from it. Biopharmaceuticals are very complicated compounds from structural point of view and for this reason, they cannot be fully characterized in terms of their structure with current analytical methods as it happens instead of low molecular weight chemicals drugs. Introduction: The regulatory guidelines require the characterization of the primary or higher sequence of these molecules and the characterization of any post-translational modifications. The use of biopharmaceuticals has really grown in the last few years: in 2016, the number of biopharmaceuticals approved by the Food and Drug Administration (FDA) and European Medicines Agency (EMA) for use in humans’ diseases was 1357. From 2013 to 2016, 73 of these compounds were approved for the treatment of cancer, inflammation, immune disorders, infections, anemia and cardiovascular diseases. Aim/Conclusion: The aim of the present review is to provide an overview of recent approaches for the characterization of biopharmaceutical products in HPLC that have been presented in the literature in the last years.

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