Molecular basis for integrin adhesion receptor binding to p21-activated kinase 4 (PAK4).

Integrin adhesion receptors provide links between extracellular ligands and cytoplasmic signaling. Multiple kinases have been found to directly engage with integrin β tails, but the molecular basis for these interactions remain unknown. Here, we assess the interaction between the kinase domain of p21-activated kinase 4 (PAK4) and the cytoplasmic tail of integrin β5.

Toxicological assessment and food allergy of silk fibroin derived from Bombyx mori cocoons.

Recent studies have demonstrated silk fibroin protein's (SF) ability to extend the shelf life of foods by mitigating the hallmarks of spoilage, namely oxidation and dehydration. Due to the potential for this protein to become more widespread, its safety was evaluated comprehensively. First, a bacterial reverse mutation test (Ames test) was conducted in five bacterial strains.

Collagen Gly missense mutations: Effect of residue identity on collagen structure and integrin binding.

Gly missense mutations in type I collagen, which replace a conserved Gly in the repeating (Gly-Xaa-Yaa) sequence with a larger residue, are known to cause Osteogenesis Imperfecta (OI). The clinical consequences of such mutations range from mild to lethal, with more serious clinical severity associated with larger Gly replacement residues. Here, we investigate the influence of the identity of the residue replacing Gly within and adjacent to the integrin binding GFPGER sequence on triple-helix structure, stability and integrin binding using a recombinant bacterial collagen system.

Mapping the Effect of Gly Mutations in Collagen on α2β1 Integrin Binding.

The replacement of one Gly in the essential repeating tripeptide sequence of the type I collagen triple helix results in the dominant hereditary bone disorder osteogenesis imperfecta. The mechanism leading to pathology likely involves misfolding and autophagy, although it has been hypothesized that some mutations interfere with known collagen interactions. Here, the effect of Gly replacements within and nearby the integrin binding GFPGER sequence was investigated using a recombinant bacterial collagen system.

Formation of multimers of bacterial collagens through introduction of specific sites for oxidative crosslinking.

A range of non-animal collagens has been described, derived from bacterial species, which form stable triple-helical structures without the need for secondary modification to include hydroxyproline in the sequence. The non-animal collagens studied to date are typically smaller than animal interstitial collagens, around one quarter the length and do not pack into large fibrillar aggregates like those that are formed by the major animal interstitial collagens. A consequence of this for biomedical products is that fabricated items, such as collagen sponges, are not as mechanically and dimensionally stable as those of animal collagens.

Synergistic effect of exogeneous and endogeneous electrostimulation on osteogenic differentiation of human mesenchymal stem cells seeded on silk scaffolds.

Bioelectrical regulation of bone fracture healing is important for many cellular events such as proliferation, migration, and differentiation. The aim of this study was to investigate the osteogenic differentiation potential of human mesenchymal stem cells (hMSCs) cultivated on silk scaffolds in response to different modes of electrostimulation (e.g.

Fibrous proteins: At the crossroads of genetic engineering and biotechnological applications.

Fibrous proteins, such as silk, elastin and collagen are finding broad impact in biomaterial systems for a range of biomedical and industrial applications. Some of the key advantages of biosynthetic fibrous proteins compared to synthetic polymers include the tailorability of sequence, protein size, degradation pattern, and mechanical properties. Recombinant DNA production and precise control over genetic sequence of these proteins allows expansion and fine tuning of material properties to meet the needs for specific applications.

Bioengineered silk gene delivery system for nuclear targeting.

Gene delivery research has gained momentum with the use of lipophilic vectors that mimic viral systems to increase transfection efficiency. Maintaining cell viability with these systems remains a major challenge. Therefore, biocompatible biopolymers that are designed by combining non-immunological viral mimicking components with suitable carrier are explored to address these limitations.

Definition of the native and denatured type II collagen binding site for fibronectin using a recombinant collagen system.

Interaction of collagen with fibronectin is important for extracellular matrix assembly and regulation of cellular processes. A fibronectin-binding region in collagen was identified using unfolded fragments, but it is not clear if the native protein binds fibronectin with the same primary sequence. A recombinant bacterial collagen is utilized to characterize the sequence requirement for fibronectin binding.

Fabrication and functionalization of hydrogels through "click" chemistry.

Hydrogels are crosslinked polymeric materials that play a vital role in many biomedical areas such as drug delivery, sensor technology, and tissue engineering. Increasing demand of these materials for such advanced applications has necessitated the development of hydrogels with complex chemical compositions such as incorporating small molecules and biomolecules that provide the functional attributes. This Focus Review highlights the tremendous impact of click chemistry on the design, synthesis, and functionalization of hydrogels.