Engineered protein cages for selective heparin encapsulation

Xiao

Front. Bioeng. Biotechnol.

et al. 2022

Bone regeneration in large segmental defects depends on the action of osteoblasts and the ingrowth of new blood vessels. Therefore, it is important to promote the release of osteogenic/angiogenic growth factors. Since the discovery of heparin, its anticoagulant, anti-inflammatory, and anticancer functions have been extensively studied for over a century. Although the application of heparin is widely used in the orthopedic field, its auxiliary effect on bone regeneration is yet to be unveiled. Specifically, approximately one-third of the transforming growth factor (TGF) superfamily is bound to heparin and heparan sulfate, among which TGF-β1, TGF-β2, and bone morphogenetic protein (BMP) are the most common growth factors used. In addition, heparin can also improve the delivery and retention of BMP-2 in vivo promoting the healing of large bone defects at hyper physiological doses. In blood vessel formation, heparin still plays an integral part of fracture healing by cooperating with the platelet-derived growth factor (PDGF). Importantly, since heparin binds to growth factors and release components in nanomaterials, it can significantly facilitate the controlled release and retention of growth factors [such as fibroblast growth factor (FGF), BMP, and PDGF] in vivo. Consequently, the knowledge of scaffolds or delivery systems composed of heparin and different biomaterials (including organic, inorganic, metal, and natural polymers) is vital for material-guided bone regeneration research. This study systematically reviews the structural properties and auxiliary functions of heparin, with an emphasis on bone regeneration and its application in biomaterials under physiological conditions.

Section: Heparin In Biomaterials Designmentioning

confidence: 99%

The Auxiliary Role of Heparin in Bone Regeneration and its Application in Bone Substitute Materials

Xiao

Front. Bioeng. Biotechnol.

et al. 2022

ACS Sustainable Chem. Eng.

“…This strategy was applied, for example, for the packaging of the fluorescent marker protein TFP in CCMV-based VLPs to avoid a dissociation of the E–K coiled-coil-based heterodimers . A more sophisticated strategy to achieve the covalent encapsulation was recently developed employing the sortase SrtA-catalyzed formation of peptide bonds between POIs and capsid proteins (Figure B). − To this end, SrtA first recognizes the sorting signal peptide (LPXTG) that can be fused, for example, to the C-terminus of POIs followed by its enzymatic cleavage. In a second catalytic reaction, the truncated signal peptide is covalently linked to a glycine-containing motif, which is fused to the N-terminus of the VLP capsid protein.…”

Section: Polyhydroxyalkanoate-based Systems and Viruslike Particlesmentioning

confidence: 99%

“…It could be shown that the encapsulation in this artificial compartment affected neither enzyme activity nor substrate diffusion and additionally exerted POI protection against proteases . In a similar approach, GFP, the T4 lysozyme, and a heparin binding peptide were covalently encapsulated by SrtA in CCMV capsids. ,, In addition to SrtA-mediated covalent linkage, sequestration of PLP-dependent tryptophanase TnaA and monooxygenase PMO to the interior surface of the SpyTag-MS2 capsid (Figure B) could be achieved by using the SpyCatcher/SpyTag system (see below).…”

Section: Polyhydroxyalkanoate-based Systems and Viruslike Particlesmentioning

confidence: 99%

“…167 In a similar approach, GFP, the T4 lysozyme, and a heparin binding peptide were covalently encapsulated by SrtA in CCMV capsids. 168,170,171 In addition to SrtA-mediated covalent linkage, sequestration of PLP-dependent tryptophanase TnaA and monooxygenase PMO to the interior surface of the SpyTag-MS2 capsid (Figure 4B) could be achieved by using the SpyCatcher/SpyTag system (see below).…”

Section: ■ Polyhydroxyalkanoate-based Systems and Viruslike Particlesmentioning

confidence: 99%

See 1 more Smart Citation

Emerging Solutions for in Vivo Biocatalyst Immobilization: Tailor-Made Catalysts for Industrial Biocatalysis

Ölçücü

Klaus

Jaeger

et al. 2021

In industry, enzymes are often immobilized to generate more stable enzyme preparations that are easier to store, handle, and recycle for repetitive use. Traditionally, enzymes are bound to inorganic carrier materials, which requires caseto-case optimization and incurs additional labor and costs. Therefore, with the advent of rational protein design strategies as part of bottom-up synthetic biology approaches, numerous immobilization methods have been developed that enable the one-step production and immobilization of enzymes onto biogenic carrier materials often directly within the production host, which we here refer to as in vivo immobilization. As a result, nano-to micro-meter-sized functionalized biomaterials, or biologically produced enzyme immobilizates, are obtained that can directly be used for synthetic purposes. In this Perspective, we provide an overview over established and recently emerging in vivo enzyme immobilization methods, with special emphasis on their applicability for (industrial) biocatalysis. For each approach, we present fundamental working principles as well as advantages and limitations guiding future research avenues toward sustainable applications in the bioindustry.

“…Together with the ability that the CP can adapt to the shape of the template, CCMV VLPs of tubular and spherical shapes were feasibly obtained by adjusting the ionic strength, as confirmed by TEM and fluorescence anisotropy (Figure 4b). Välimäki et al conjugated a heparin-specific peptide (HBP) to the CP N-terminus with the SrtA-based method and approximately 25% of the CPs were successfully conjugated [61]. The addition of heparin triggered the CCMV VLP formation through charge-charge interactions between heparin and HBP.…”

Section: Ccmvmentioning

confidence: 99%

Polyelectrolyte Encapsulation and Confinement within Protein Cage-Inspired Nanocompartments

et al. 2021

Self Cite

Protein cages are nanocompartments with a well-defined structure and monodisperse size. They are composed of several individual subunits and can be categorized as viral and non-viral protein cages. Native viral cages often exhibit a cationic interior, which binds the anionic nucleic acid genome through electrostatic interactions leading to efficient encapsulation. Non-viral cages can carry various cargo, ranging from small molecules to inorganic nanoparticles. Both cage types can be functionalized at targeted locations through genetic engineering or chemical modification to entrap materials through interactions that are inaccessible to wild-type cages. Moreover, the limited number of constitutional subunits ease the modification efforts, because a single modification on the subunit can lead to multiple functional sites on the cage surface. Increasing efforts have also been dedicated to the assembly of protein cage-mimicking structures or templated protein coatings. This review focuses on native and modified protein cages that have been used to encapsulate and package polyelectrolyte cargos and on the electrostatic interactions that are the driving force for the assembly of such structures. Selective encapsulation can protect the payload from the surroundings, shield the potential toxicity or even enhance the intended performance of the payload, which is appealing in drug or gene delivery and imaging.