Search results for "Spicule"

The role of the silicatein-alpha interactor silintaphin-1 in biomimetic biomineralization.

2008

Biosilicification in sponges is initiated by formation of proteinaceous filaments, predominantly consisting of silicateins. Silicateins enzymatically catalyze condensation of silica nanospheres, resulting in symmetric skeletal elements (spicules). In order to create tailored biosilica structures in biomimetic approaches it is mandatory to elucidate proteins that are fundamental for the assembly of filaments. Silintaphin-1 is a core component of modularized filaments and also part of a spicule-enfolding layer. It bears no resemblance to other proteins, except for the presence of an interaction domain that is fundamental for its function as scaffold/template. In the presence of silicatein sil…

Cover Picture: NanoSIMS: Insights into the Organization of the Proteinaceous Scaffold within Hexactinellid Sponge Spicules (ChemBioChem 8/2010)

2010

NanoSIMS: insights into the organization of the proteinaceous scaffold within Hexactinellid sponge spicules.

2010

The giant basal spicules (GBS) from Monorhaphis chuni (Porifera [sponges], Hexactinellida) represent the largest biosilica structures on Earth and can reach lengths of 300 cm (diameter of 1.1 cm). The amorphous silica of the inorganic matrix is formed enzymatically by silicatein. During this process, the enzyme remains trapped inside the lamellar-organized spicules. In order to localize the organic silicatein scaffold, the inside of a lamella has been analyzed by nano-secondary ion mass spectrometry (NanoSIMS). It is shown that the GBSs are composed of around 245 concentrically arranged individual siliceous lamellae. These surround an internal siliceous axial cylinder. The lamellae adjacent…

A synthetic biology approach for the fabrication of functional (fluorescent magnetic) bioorganic–inorganic hybrid materials in sponge primmorphs

2020

During evolution, sponges (Porifera) have honed the genetic toolbox and biosynthetic mechanisms for the fabrication of siliceous skeletal components (spicules). Spicules carry a protein scaffold embedded within biogenic silica (biosilica) and feature an amazing range of optical, structural, and mechanical properties. Thus, it is tempting to explore the low-energy synthetic pathways of spiculogenesis for the fabrication of innovative hybrid materials. In this synthetic biology approach, the uptake of multifunctional nonbiogenic nanoparticles (fluorescent, superparamagnetic) by spicule-forming cells of bioreactor-cultivated sponge primmorphs provides access to spiculogenesis. The ingested nan…

Molecular Mechanism of Spicule Formation in the Demosponge Suberites domuncula: Silicatein-Collagen-Myotrophin

2003

In living organisms four major groups of biominerals exist: (1) iron compounds, which are restricted primarily to Prokaryota; (2) calcium phosphates, found in Metazoa; (3) calcium carbonates, used by Prokaryota, Protozoa, Plantae, Fungi and Metazoa and (4) silica (opal) present in sponges and diatoms (reviewed in: Bengtson 1994; Baeuerlein 2000). It is surprising that the occurrence of silica as a major skeletal element is restricted to some Protozoa and to sponges (Porifera). The element silicon (Si) contributes to 28% of the earth crust and is - after oxygen - the second most abundant element on earth (Windholz 1983).

Sustainable Exploitation and Conservation of the Endemic Lake Baikal Sponge (Lubomirskia baicalensis) for Application in Nanobiotechnology

2009

The large sub-continent of Siberia is one of the richest mineral and oil resources on Earth. In its center, one region has gained prominence: Lake Baikal. It is one of the oldest, the deepest, and the lake with the greatest volume on Earth and is inhabited by more than 1,500 endemic species. It was Pallas (1771) who discovered in the lake a sponge species, Lubomirskia baicalensis (Porifera: Demospongiae), which dominates Lake Baikal's littoral-zone benthos. This sponge species has a distinguished, pronounced body plan which is composed of modules. The application of molecular biological and cell biological techniques has allowed an insight into the richness of the genomic regulatory systems…

The Unique Invention of the Siliceous Sponges: Their Enzymatically Made Bio-Silica Skeleton

2011

Sponges are sessile filter feeders that, among the metazoans, evolved first on Earth. In the two classes of the siliceous sponges (the Demospongiae and the Hexactinellida), the complex filigreed body is stabilized by an inorganic skeleton composed of amorphous silica providing them a distinct body shape and plan. It is proposed that the key innovation that allowed the earliest metazoans to form larger specimens was the enzyme silicatein. This enzyme is crucial for the formation of the siliceous skeleton. The first sponge fossils with body preservation were dated back prior to the “Precambrian-Cambrian” boundary [Vendian (610–545 Ma)/Ediacaran (542–580 Ma)]. A further molecule required for t…

Biogenic Inorganic Polysilicates (Biosilica): Formation and Biomedical Applications

2013

The siliceous sponges, the demosponges and hexactinellid glass sponges, are unique in their ability to form biosilica structures with complex architectures through an enzyme-catalyzed mechanism. The biosilica skeleton of these sponges with its hierarchically structure and exceptional opto-mechanical properties has turned out to be an excellent model for the design of biomimetic nanomaterials with novel property combinations. In addition, biosilica shows morphogenetic activity that offers novel applications in the field of bone tissue engineering and repair. In recent years, much progress has been achieved towards the understanding of the principal enzymes, the silicateins that form the spon…

Enzymatically Synthesized Biosilica

2015

Structural biomaterials are hierarchically organized and biofabricated. Biosilica represents the main mineral component of the sponge skeletal elements, the spicules. We summarize recent data on the different levels of molecular, biological, and structural hierarchies controlling the synthesis of the picturesquely and intricately architectured spicules/skeletons.

A cryptochrome-based photosensory system in the siliceous sponge Suberites domuncula (Demospongiae)

2010

Based on the light-reactive behavior of siliceous sponges, their intriguing quartz glass-based spicular system and the existence of a light-generating luciferase [Muller WEG et al. (2009) Cell Mol Life Sci 66, 537–552], a protein potentially involved in light reception has been identified, cloned and recombinantly expressed from the demosponge Suberites domuncula. Its sequence displays two domains characteristic of cryptochrome, the N-terminal photolyase-related region and the C-terminal FAD-binding domain. The expression level of S. domuncula cryptochrome depends on animal’s exposure to light and is highest in tissue regions rich in siliceous spicules; in the dark, no cryptochrome transcri…