scholarly journals On the Nanomechanical and Viscoelastic Properties of Coatings Made of Recombinant Sea Star Adhesive Proteins

2021 ◽  
Vol 7 ◽  
Author(s):  
Mathilde Lefevre ◽  
Thi Quynh Tran ◽  
Thomas De Muijlder ◽  
Bede Pittenger ◽  
Patrick Flammang ◽  
...  
Keyword(s):  
Recombinant Proteins ◽  
Metal Binding ◽  
Specific Protein ◽  
Major Constituent ◽  
Sea Star ◽  
Sea Stars ◽  
Properties Of Coatings ◽  
Adhesive Properties ◽  
Nanomechanical Properties ◽  
Adhesive Proteins

To attach to surfaces in the sea, sea stars produce proteinaceous adhesive secretions. Sfp1 is a major constituent of this adhesive, where it is present in the form of four subunits (named Sfp1α to δ) displaying specific protein-, carbohydrate- and metal-binding domains. Recently, two recombinant proteins inspired from Sfp1 have been produced: one corresponding to the C-terminal part of Sfp1β and the other to the full-length Sfp1δ. Adsorption ability tests showed that both recombinant proteins were able to adsorb and to form coatings on different surfaces in artificial seawater as well as in Tris buffer supplemented with NaCl or CaCl2. In this study, we used Atomic Force Microscopy (AFM) to characterize the nanomechanical properties of these coatings with an emphasis on functional characteristics such as adhesive properties and modulus of elasticity. We used AFM techniques which are the most appropriate to characterize the coating microstructure combined with the mapping of its nanomechanical properties.

scholarly journals Interspecies comparison of sea star adhesive proteins

2019 ◽  
Vol 374 (1784) ◽  
pp. 20190195 ◽  
Author(s):  
Birgit Lengerer ◽  
Morgane Algrain ◽  
Mathilde Lefevre ◽  
Jérôme Delroisse ◽  
Elise Hennebert ◽  
...  
Keyword(s):  
Potential Surface ◽  
Secretory Cells ◽  
Sea Star ◽  
Surface Binding ◽  
Sea Stars ◽  
Adhesive Material ◽  
High Conservation ◽  
The Common ◽  
Adhesive Proteins ◽  
Tube Feet

Sea stars use adhesive secretions to attach their numerous tube feet strongly and temporarily to diverse surfaces. After detachment of the tube feet, the adhesive material stays bound to the substrate as so-called ‘footprints’. In the common sea star species Asterias rubens , the adhesive material has been studied extensively and the first sea star footprint protein (Sfp1) has been characterized. We identified Sfp1-like sequences in 17 additional sea star species, representing different taxa and tube foot morphologies, and analysed the evolutionary conservation of this protein. In A. rubens , we confirmed the expression of 34 footprint proteins in the tube foot adhesive epidermis, with 22 being exclusively expressed in secretory cells of the adhesive epidermis and 12 showing an additional expression in the stem epidermis. The sequences were used for BLAST searches in seven asteroid transcriptomes providing a first insight in the conservation of footprint proteins among sea stars. Our results highlighted a high conservation of the large proteins making up the structural core of the footprints, whereas smaller, potential surface-binding proteins might be more variable among sea star species. This article is part of the theme issue ‘Transdisciplinary approaches to the study of adhesion and adhesives in biological systems’.

scholarly journals Sea stars generate downforce to stay attached to surfaces

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mark Hermes ◽  
Mitul Luhar
Keyword(s):  
Body Shape ◽  
Control Volume ◽  
Water Channel ◽  
Morphological Plasticity ◽  
The Body ◽  
Sea Star ◽  
Sea Stars ◽  
Hydrodynamic Loads ◽  
Spherical Dome ◽  
Star Models

AbstractIntertidal sea stars often function in environments with extreme hydrodynamic loads that can compromise their ability to remain attached to surfaces. While behavioral responses such as burrowing into sand or sheltering in rock crevices can help minimize hydrodynamic loads, previous work shows that sea stars also alter body shape in response to flow conditions. This morphological plasticity suggests that sea star body shape may play an important hydrodynamic role. In this study, we measured the fluid forces acting on surface-mounted sea star and spherical dome models in water channel tests. All sea star models created downforce, i.e., the fluid pushed the body towards the surface. In contrast, the spherical dome generated lift. We also used Particle Image Velocimetry (PIV) to measure the midplane flow field around the models. Control volume analyses based on the PIV data show that downforce arises because the sea star bodies serve as ramps that divert fluid away from the surface. These observations are further rationalized using force predictions and flow visualizations from numerical simulations. The discovery of downforce generation could explain why sea stars are shaped as they are: the pentaradial geometry aids attachment to surfaces in the presence of high hydrodynamic loads.

scholarly journals Binding of Gd3+to the neuronal signalling protein calexcitin identifies an exchangeable Ca2+-binding site

2016 ◽  
Vol 72 (4) ◽  
pp. 276-281
Author(s):  
Lucas Chataigner ◽  
Jingxu Guo ◽  
Peter T. Erskine ◽  
Alun R. Coker ◽  
Steve P. Wood ◽  
...  
Keyword(s):  
Metal Ions ◽  
Binding Site ◽  
Metal Binding ◽  
Calcium Signalling ◽  
Specific Protein ◽  
Metal Binding Sites ◽  
Calcium Sensing ◽  
Neuronal Signalling ◽  
Ef Hand ◽  
Ef Hands

Calexcitin was first identified in the marine snailHermissenda crassicornisas a neuronal-specific protein that becomes upregulated and phosphorylated in associative learning. Calexcitin possesses four EF-hand motifs, but only the first three (EF-1 to EF-3) are involved in binding metal ions. Past work has indicated that under physiological conditions EF-1 and EF-2 bind Mg2+and Ca2+, while EF-3 is likely to bind only Ca2+. The fourth EF-hand is nonfunctional owing to a lack of key metal-binding residues. The aim of this study was to use a crystallographic approach to determine which of the three metal-binding sites of calexcitin is most readily replaced by exogenous metal ions, potentially shedding light on which of the EF-hands play a `sensory' role in neuronal calcium signalling. By co-crystallizing recombinant calexcitin with equimolar Gd3+in the presence of trace Ca2+, EF-1 was shown to become fully occupied by Gd3+ions, while the other two sites remain fully occupied by Ca2+. The structure of the Gd3+–calexcitin complex has been refined to anRfactor of 21.5% and anRfreeof 30.4% at 2.2 Å resolution. These findings suggest that EF-1 of calexcitin is the Ca2+-binding site with the lowest selectivity for Ca2+, and the implications of this finding for calcium sensing in neuronal signalling pathways are discussed.

Sea star-inspired recombinant adhesive proteins self-assemble and adsorb on surfaces in aqueous environments to form cytocompatible coatings

2020 ◽  
Vol 112 ◽  
pp. 62-74
Author(s):  
Mathilde Lefevre ◽  
Patrick Flammang ◽  
A. Sesilja Aranko ◽  
Markus B. Linder ◽  
Thomas Scheibel ◽  
...  
Keyword(s):  
Sea Star ◽  
Aqueous Environments ◽  
Adhesive Proteins

?Tethyaster albertensis, a Late Cretaceous (Turonian) sea star from the Cardium Formation, Alberta, Canada

1990 ◽  
Vol 64 (6) ◽  
pp. 1045-1049 ◽  
Author(s):  
Russell L. Hall ◽  
Suzan Moore
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
Sea Star ◽  
Sea Stars ◽  
Peace River ◽  
The North ◽  
The Family ◽  
Cardium Formation ◽  
Northern Alberta ◽  
Limited Change

Although many of the surviving lineages of sea stars appeared during an early Mesozoic radiation of the class and have undergone limited change since then, they have left a very poor fossil record, particularly in the Mesozoic of North America (Blake, 1981). This record from the Late Cretaceous of Alberta is made more significant by the fact that it is apparently only the second occurrence of a member of the family Astropectinidae in the Cretaceous of North America; Lophidiaster silentiensis was described by McLearn (1944) from the Lower Cretaceous (Albian) Hasler Formation, from a now-submerged locality on the Peace River in northern Alberta. All previously recorded fossil sea stars from the North American Cretaceous are representatives of the family Goniasteridae.

scholarly journals Expression of Functional Recombinant Mussel Adhesive Protein Mgfp-5 in Escherichia coli

2004 ◽  
Vol 70 (6) ◽  
pp. 3352-3359 ◽  
Author(s):  
Dong Soo Hwang ◽  
Hyo Jin Yoo ◽  
Jong Hyub Jun ◽  
Won Kyu Moon ◽  
Hyung Joon Cha
Keyword(s):  
Escherichia Coli ◽  
Adhesion Force ◽  
Soluble Form ◽  
Material Surface ◽  
Adhesive Properties ◽  
Affinity Ligand ◽  
Mussel Adhesive Proteins ◽  
Mussel Adhesive ◽  
Aqueous Conditions ◽  
Adhesive Proteins

ABSTRACT Mussel adhesive proteins have been suggested as a basis for environmentally friendly adhesives for use in aqueous conditions and in medicine. However, attempts to produce functional and economical recombinant mussel adhesive proteins (mainly foot protein type 1) in several systems have failed. Here, the cDNA coding for Mytilus galloprovincialis foot protein type 5 (Mgfp-5) was isolated for the first time. Using this cDNA, we produced a recombinant Mgfp-5 fused with a hexahistidine affinity ligand, which was expressed in a soluble form in Escherichia coli and was highly purified using affinity chromatography. The adhesive properties of purified recombinant Mgfp-5 were compared with the commercial extracted mussel adhesive Cell-Tak by investigating adhesion force using atomic force microscopy, material surface coating, and quartz crystal microbalance. Even though further macroscale assays are needed, these microscale assays showed that recombinant Mgfp-5 has significant adhesive ability and may be useful as a bioadhesive in medical or underwater environments.

Behavioral interactions between the actinian Tealia piscivora (Anthozoa: Actiniaria) and the asteroid Dermasterias imbricata

1985 ◽  
Vol 63 (8) ◽  
pp. 1921-1929 ◽  
Author(s):  
Joel Elliott ◽  
James Dalby Jr. ◽  
R. Cohen ◽  
D. M. Ross
Keyword(s):  
Sea Anemone ◽  
Sea Star ◽  
Sea Stars ◽  
Behavioral Interactions ◽  
Size Dependent ◽  
Intermediate Size

Interactions between the sea anemone Tealia piscivora and the sea star Dermasterias imbricata have been studied in the laboratory and in subtidal habitats. Dermasterias causes the release of the pedal disk of smaller T. piscivora. The response is specific. Nineteen other sea stars did not cause release; four other species of Tealia did not respond to Dermasterias. The response is size dependent; unfailing and quick in small T. piscivora, less frequent and slow in those of intermediate size, it did not occur at all in large specimens. Unrestrained T. piscivora generally survived interactions with Dermasterias but when prevented from detaching, most of the small anemones were devoured. Tealia piscivora have been observed to detach and engulf small Dermasterias. Most small anemones were found at greater depths; most large anemones were found at lesser depths where Dermasterias were most abundant. It is suggested that by releasing the pedal disk, small T. piscivora eventually end up in deeper water where there are few Dermasterias and thus the anemones escape predation.

scholarly journals Isolation and identification of metallothionein isoforms (MT-1 and MT-2) in the rat testis

1998 ◽  
Vol 334 (3) ◽  
pp. 695-701 ◽  
Author(s):  
Junko S. SUZUKI ◽  
Naomi KODAMA ◽  
Andrei MOLOTKOV ◽  
Etsuko AOKI ◽  
Chiharu TOHYAMA
Keyword(s):  
Metal Binding ◽  
Binding Proteins ◽  
Gel Filtration ◽  
Specific Protein ◽  
Composition Analysis ◽  
Isolation And Identification ◽  
Rat Testis ◽  
Heavy Metal Binding ◽  
Protein Fragmentation ◽  
Male Genital

It has been a long-lasting controversial issue as to whether or not the male genital organs, such as the testis and prostate, contain metallothioneins (MTs), a group of cysteine-rich heavy-metal-binding proteins that play a role in detoxifying heavy metals such as cadmium (Cd). Earlier studies reported that the rodent testis lacks MTs and concluded that this is why the testis is very susceptible to Cd, although other indirect experimental evidence suggests that MTs are present in this organ. A deficiency of MTs in the testis was originally suspected on the basis of amino acid composition analysis, since MT-like proteins isolated as Cd-binding proteins did not have a characteristic MT structure. In the present study, we demonstrate that the rat testis indeed expresses Cd-binding proteins with sequences identical to those previously described for MT-1 and MT-2, the major isoforms. To confirm that MT-1 and MT-2 are present in the rat testis, we purified and isolated Cd-binding proteins by homogenization using Cd-containing buffer, followed by sequential purification using Sephadex G-75 gel filtration chromatography and anion HPLC column chromatography, which yielded Cd-binding protein-1 (Cd-BP-1) and -2 (Cd-BP-2). After pyridylethylation, Cd-BP-1 and Cd-BP-2 were subjected to specific protein fragmentation by acids and endopeptidases, which revealed that these Cd-binding proteins have the same primary structures as MT-1 and MT-2 respectively. Thus we believe that the present results clearly resolve the long-standing debate about the presence of MTs in the testis, at least in the rodent.

scholarly journals Competitors as accomplices: seaweed competitors hide corals from predatory sea stars

2015 ◽  
Vol 282 (1814) ◽  
pp. 20150714 ◽  
Author(s):  
Cody S. Clements ◽  
Mark E. Hay
Keyword(s):  
Field Experiments ◽  
Coral Cover ◽  
Ecological Communities ◽  
Protective Effects ◽  
Sea Star ◽  
Sea Stars ◽  
Macroalgal Blooms ◽  
Feeding Experiments ◽  
High Preference ◽  
And Function

Indirect biotic effects arising from multispecies interactions can alter the structure and function of ecological communities—often in surprising ways that can vary in direction and magnitude. On Pacific coral reefs, predation by the crown-of-thorns sea star, Acanthaster planci , is associated with broad-scale losses of coral cover and increases of macroalgal cover. Macroalgal blooms increase coral–macroalgal competition and can generate further coral decline. However, using a combination of manipulative field experiments and observations, we demonstrate that macroalgae, such as Sargassum polycystum , produce associational refuges for corals and dramatically reduce their consumption by Acanthaster . Thus, as Acanthaster densities increase, macroalgae can become coral mutualists, despite being competitors that significantly suppress coral growth. Field feeding experiments revealed that the protective effects of macroalgae were strong enough to cause Acanthaster to consume low-preference corals instead of high-preference corals surrounded by macroalgae. This highlights the context-dependent nature of coral–algal interactions when consumers are common. Macroalgal creation of associational refuges from Acanthaster predation may have important implications for the structure, function and resilience of reef communities subject to an increasing number of biotic disturbances.

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