Multiple Protein Subunits Research Articles

Engineering Cu–Ce-a nanozymes: Revolutionary alloy nanomaterials mimicking cytochrome c oxidase for ultra-sensitive cytochrome c detection

The design of synthetic analogs of cytochrome c oxidase (CcO) is a formidable task due to its intricate structure encompassing multiple metal prosthetic sites and protein subunits. In recent years, artificial enzymes based on alloy nanomaterials have garnered significant attention due to the alloy design approach holds promise for the effective tuning of the properties of metal catalysts. In this study, we present copper-cerium alloy nanozymes (Cu–Ce-a NEs), where Cu mimics the active site of CcO, while Ce endows the alloy phase and enhances the capacity to catalyze the oxidation to cytochrome c (Cyt c). Cu–Ce-a NEs functionally mimics CcO, the terminal enzyme in the respiratory electron transport chain (ETC), by catalyzing the four-electron reduction of dioxygen to water. Utilizing the CcO-like properties of Cu–Ce-a NEs, we successfully implemented the electrochemical detection of Cyt c. The Cu–Ce-a NEs based electrochemical sensor revealed a favorable linear range spanning from 2 to 20 μM Cyt c, with a detection limit (LOD) of 2 μM. This method demonstrates high accuracy in Cyt c quantitation in pharmaceuticals, with results closely aligning with the actual concentrations. This finding not only offers new perspectives in the design of enzyme analogs, but also underscores the potential of this method for clinical Cyt c detection, highlighting its significance in biomedical research and diagnostics.

Abstract 4977: Development of small molecule inhibitors of protein interaction with glycosaminoglycans

Abstract Glycosaminoglycans (GAGs), such as heparan sulfate and chondroitin sulfate, are an important component of the tumor microenvironment (TME). These carbohydrates are attached to proteoglycans at the surface of tumor cells and play a vital role in malignant transformation. Heparan sulfate (HS) glycosaminoglycans have been demonstrated to play a pleiotropic role in regulating the activity of important cellular receptors and downstream signaling pathways, and are implicated in cancer cell proliferation, angiogenesis, invasion, and metastasis. Heparinase, an endoglycosidase that specifically cleaves heparan sulfate side chains of heparan sulfate proteoglycans is expressed in several sarcoma subtypes. We measured heparinase activity in several cell lines and found that A673, CHP100, CHLA9 and RD-ES Ewing’s sarcoma cell lines have significantly higher levels of heparinase activity compared to the heparinase-deficient CHO-K1 psgD-677 cell line. Interference with heparinase or heparin sulfate function(s) may represent a therapeutic approach in sarcoma. To this end, we tested these cell lines by measuring cell growth using a cell viability assay, in the presence or absence of GTC3300P, a small molecule inhibitor of protein interaction with glycosaminoglycan. We demonstrate that the Ewing’s sarcoma cell lines exhibit potent and significant inhibition in cell growth in vitro, in the presence of drug. Western blot analysis shows induction of cleaved Poly-ADP Ribose Polymerase (PARP), yH2AX, as well as cleaved caspase-3, known markers of apoptosis and down regulation of mTORC1 targets such as phospho-S6 (p-S6), in Ewing’s sarcoma. Apoptosis was confirmed by the induction of sub-G1 population in Ewing’s sarcoma by cell cycle analysis. Previous reports have indicated that heparinase activity is strongly implicated in cell migration and invasion and is associated with tumor metastasis, angiogenesis and inflammation. This was confirmed by LC-MS/MS proteomics and bioinformatics (gene ontology and gene set enrichment) analysis of these multiple cell lines, which identified alterations in numerous biomarkers in these pathways, including multiple ribosomal protein subunits, spliceosomes components, and complement coagulation cascade. We further conducted a cell migration assay and demonstrate that GTC3300 significantly inhibits cell migration in Ewing’s sarcoma cell lines, but not in heparinase-deficient psg677 cells. Taken together our data strongly suggests that targeting protein interaction with glycosaminoglycans including heparan sulfate in Ewing’s sarcoma represents a novel approach and merits further investigation Citation Format: Tahir N. Sheikh, Elgilda Musi, Alex J. Rai, Gary K. Schwartz. Development of small molecule inhibitors of protein interaction with glycosaminoglycans. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4977.

Mapping of RNase P Ribozyme Regions in Proximity with a Human RNase P Subunit Protein Using Fe(II)-EDTA Cleavage and Nuclease Footprint Analyses.

Ribonuclease P (RNase P), which may consist of both protein subunits and a catalytic RNA part, is responsible for 5' maturation of tRNA by cleaving the 5'-leader sequence. In Escherichia coli, RNase P contains a catalytic RNA subunit (M1 RNA) and a protein factor (C5 protein). In human cells, RNase P holoenzyme consists of an RNA subunit (H1 RNA) and multiple protein subunits that include human RPP29 protein. M1GS, a sequence specific targeting ribozyme derived from M1 RNA, can be constructed to target a specific mRNA to degrade it in vitro. Recent studies have shown that M1GS ribozymes are efficient in blocking the expression of viral mRNAs in cultured cells and in animals. These results suggest that RNase P ribozymes have the potential to be useful in basic research and in clinical applications. It has been shown that RNase P binding proteins, such as C5 protein and RPP29, can enhance the activities of M1GS RNA in processing a natural tRNA substrate and a target mRNA. Understanding how RPP29 binds to M1GS RNA and enhances the enzyme's catalytic activity will provide great insight into developing more robust gene-targeting ribozymes for in vivo application. In this chapter, we describe the methods of using Fe(II)-ethylenediaminetetraacetic acid (EDTA) cleavage and nuclease footprint analyses to determine the regions of a M1GS ribozyme that are in proximity to RPP29 protein.

A modular and self-adjuvanted multivalent vaccine platform based on porcine circovirus virus-like nanoparticles

BackgroundVirus-like particles (VLPs) are supramolecular structures composed of multiple protein subunits and resemble natural virus particles in structure and size, making them highly immunogenic materials for the development of next-generation subunit vaccines. The orderly and repetitive display of antigenic epitopes on particle surface allows efficient recognition and cross-link by B cell receptors (BCRs), thereby inducing higher levels of neutralizing antibodies and cellular immune responses than regular subunit vaccines. Here, we present a novel multiple antigen delivery system using SpyCatcher/Spytag strategy and self-assembled VLPs formed by porcine circovirus type 2 (PCV2) Cap, a widely used swine vaccine in solo.ResultsCap-SC, recombinant Cap with a truncated SpyCatcher polypeptide at its C-terminal, self-assembled into 26-nm VLPs. Based on isopeptide bonds formed between SpyCatcher and SpyTag, classical swine fever virus (CSFV) E2, the antigen of interest, was linked to SpyTag and readily surface-displayed on SpyCatcher decorated Cap-SC via in vitro covalent conjugation. E2-conjugated Cap VLPs (Cap-E2 NPs) could be preferentially captured by antigen presenting cells (APCs) and effectively stimulate APC maturation and cytokine production. In vivo studies confirmed that Cap-E2 NPs elicited an enhanced E2 specific IgG response, which was significantly higher than soluble E2, or the admixture of Cap VLPs and E2. Moreover, E2 displayed on the surface did not mask the immunodominant epitopes of Cap-SC VLPs, and Cap-E2 NPs induced Cap-specific antibody levels and neutralizing antibody levels comparable to native Cap VLPs.ConclusionThese results demonstrate that this modularly assembled Cap-E2 NPs retains the immune potential of Cap VLP backbone, while the surface-displayed antigen significantly elevated E2-induced immune potency. This immune strategy provides distinctly improved efficacy than conventional vaccine combination. It can be further applied to the development of dual or multiple nanoparticle vaccines to prevent co-infection of PCV2 and other swine pathogens.

Modeling the kinetics of heteromeric potassium channels.

Mechanistic mathematical modeling has long been used as a tool for answering questions in cellular physiology. To mathematically describe cellular processes such as cell excitability, volume regulation, neurotransmitter release, and hormone secretion requires accurate descriptions of ion channel kinetics. One class of ion channels currently lacking a physiological model framework is the class of channels built with multiple different potassium protein subunits called heteromeric voltage gated potassium channels. Here we present a novel mathematical model for heteromeric potassium channels that captures both the number and type of protein subunits present in each channel. Key model assumptions are validated by showing our model is the reduction of a Markov model and through observations about voltage clamp data. We then show our model's success in replicating kinetic properties of concatemeric channels with different numbers of K v 1.1 and K v 1.2 subunits. Finally, through comparisons with multiple expression experiments across multiple voltage gated potassium families, we use the model to make predictions about the importance and effect of genetic mutations in heteromeric channel formation.

Shape-Morphing of an Artificial Protein Cage with Unusual Geometry Induced by a Single Amino Acid Change.

Artificial protein cages are constructed from multiple protein subunits. The interaction between the subunits, notably the angle formed between them, controls the geometry of the resulting cage. Here, using the artificial protein cage, “TRAP-cage”, we show that a simple alteration in the position of a single amino acid responsible for Au(I)-mediated subunit–subunit interactions in the constituent ring-shaped building blocks results in a more acute dihedral angle between them. In turn, this causes a dramatic shift in the structure from a 24-ring cage with an octahedral symmetry to a 20-ring cage with a C2 symmetry. This symmetry change is accompanied by a decrease in the number of Au(I)-mediated bonds between cysteines and a concomitant change in biophysical properties of the cage.

Development of antibacterial Type III secretion system binding antibodies

Common agricultural crops such as wild rice and tomatoes are infected by the bacterial pathogens Xanthomonas Oryzae pv. oryzae and Pseudomonas Syringae pv. syringae respectively. These species use the same cellular structure to infect their host cells called a type three secretion system or T3SS. T3SSs are composed of multiple protein subunits used to insert effector proteins into the host cell's cytoplasm. These effectors in turn begin a cascade of events that ultimately results in invasion of the host cell. Once infected, the pathogens can take over the cell’s system and ultimately kill it. Given the importance of tomatoes and rice as food sources, the spread of these infections could potentially become disastrous for the populations that depend on them. To combat this infection, biological antibiotics will be developed to bind to a critical subunit in each of the respective pathogen’s T3SS, preventing proper assembly and function, and rendering the bacteria non‐pathogenic.A combination of yeast surface display and directed evolution are being used to find nanobodies specific to the T3SS in Xanthomonas Oryzae pv. oryzae and Pseudomonas Syringae pv. syringae. Nanobodies are inexpensive and stable antibody fragments that hold substantial potential as antimicrobials in human and agriscience applications. To do this, an antigen mimicking that of the bacterial secretion systems must be created. The antigens herein were chosen for their relative conservation and role in T3SS pathogenicity. This antigen selection strategy is expected to both increase the applicability of the method across bacterial species, and reduce the potential for the development of antibiotic resistance. This poster outlines the selection, cloning, and purification of a T3SS antigen for directed evolution of nanobodies as T3SS‐targeting antimicrobials.

Rapid cell-free characterization of multi-subunit CRISPR effectors and transposons

CRISPR-Cas biology and technologies have been largely shaped to date by the characterization and use ofsingle-effector nucleases. By contrast, multi-subunit effectors dominate natural systems, represent emerging technologies, and were recently associated with RNA-guided DNA transposition. This disconnect stems from the challenge of working with multiple protein subunits invitro and invivo. Here, we apply cell-free transcription-translation (TXTL) systems to radically accelerate the characterization of multi-subunit CRISPR effectors and transposons. Numerous DNA constructs can be combined in one TXTL reaction, yielding defined biomolecular readouts in hours. Using TXTL, we mined phylogenetically diverse I-E effectors, interrogated extensively self-targeting I-C and I-F systems, and elucidated targeting rules for I-B and I-F CRISPR transposons using only DNA-binding components. We further recapitulated DNA transposition in TXTL, which helped reveal a distinct branch of I-B CRISPR transposons. These capabilities will facilitate the study and exploitation of the broad yet underexplored diversity of CRISPR-Cas systems and transposons.

Twisted rectangular subunits self-assemble into a ferritin-like capsule

<h2>Summary</h2> The vertices of polyhedral protein capsules are spanned by multiple capsule-forming protein subunits, thus enclosing more volume and larger cargoes than if single proteins connected vertices directly. Application of protein cage design principles to synthetic analogs would allow a given ligand to enclose a greater volume. Here, we report the self-assembly of a simple tetramine subcomponent into a tetrahedral metal-organic capsule, with each face of the capsule composed of three ligand panels. The edges of the capsule are 31.8 Å in length—double the distance that can be spanned by a single subcomponent. The self-assembly rules followed by this system are programmed into the tetramine—it twists out of planarity in its lowest-energy configuration, thus favoring the large capsule over a simpler cube-like architecture. Unlike other large metal-organic capsules, the cavity of this new capsule is enclosed, and the structure was observed to bind large dianionic guests.

Depletion of SMARCB1 and BRD7, two SWI/SNF chromatin remodelling complex subunits, differentially impact porcine embryo development.

SWI/SNF chromatin remodelling complexes are composed of multiple protein subunits and can be categorised into three sub-families, including the BAF, PBAF, and GBAF complexes. We hypothesised that depletion of SMARCB1 and BRD7, two subunits unique to different SWI/SNF sub-families, would differentially impact porcine embryo development. The aim of these experiments was to determine the developmental requirements of two SWI/SNF subunits, SMARCB1 and BRD7. RNA interference assays were used to determine the developmental requirements of SMARCB1 and BRD7 in porcine embryos. Our findings indicate that knockdown of SMARCB1 dramatically reduces embryo developmental potential, with few embryos developing beyond the pronuclear stage. The knockdown of BRD7 had a less severe impact on developmental potential. Our findings also demonstrate that knockdown of SMARCB1 alters the expression of NANOG and POU5F1 (also referred to as OCT4 ). These findings highlight the unique developmental requirements for sub-families of SWI/SNF chromatin remodelling complexes. This new knowledge will enable us to determine how discrete genomic loci are differentially remodelled during key points in embryo development.

The Pore-Forming Hemolysin BL Enterotoxin from Bacillus cereus: Subunit Interactions in Cell-Free Systems.

The tripartite enterotoxin Hemolysin BL (Hbl) has been widely characterized as a hemolytic and cytotoxic virulence factor involved in foodborne diarrheal illness caused by Bacillus cereus. Previous studies have described the formation of the Hbl complex and aimed to identify the toxin’s mode of action. In this study, we analyzed the assembly of Hbl out of its three individual subunits L1, L2 and B in a soluble as well as a putative membrane bound composition using a Chinese hamster ovary (CHO) cell-free system. Subunits were either coexpressed or synthesized individually in separate cell-free reactions and mixed together afterwards. Hemolytic activity of cell-free synthesized subunits was demonstrated on 5% sheep blood agar and identified both synthesis procedures, coexpression as well as individual synthesis of each subunit, as functional for the synthesis of an active Hbl complex. Hbl’s ability to perforate cell membranes was evaluated using a propidium iodide uptake assay. These data suggested that coexpressed Hbl subunits augmented cytotoxic activity with increasing concentrations. Further, a pre-pore-complex of L1-L2 showed cytotoxic effects suggesting the possibility of an interaction between the cell membrane and the pre-pore-complex. Overall, this study shows that cell-free protein synthesis is a fast and efficient way to study the assembly of multiple protein subunits in soluble as well as vesicular fractions.

Protein cages as building blocks for superstructures.

Proteins naturally self-assemble to function. Protein cages result from the self-assembly of multiple protein subunits that interact to form hollow symmetrical structures with functions that range from cargo storage to catalysis. Driven by self-assembly, building elegant higher-order superstructures with protein cages as building blocks has been an increasingly attractive field in recent years. It presents an engineering challenge not only at the molecular level but also at the supramolecular level. The higher-order constructs are proposed to provide access to diverse functional materials. Focussing on design strategy as a perspective, current work on protein cage supramolecular self-assembly are reviewed from three principles that are electrostatic, metal-ligand coordination and inherent symmetry. The review also summarises possible applications of the superstructure architecture built using modified protein cages.

The OP Protein Cage: A Versatile Molecular Delivery Platform.

Well-defined containers constructed from multiple protein subunits are a unique class of nanomaterial useful in supramolecular chemistry and biology. These protein cages are widespread in nature, where they are responsible for a diversity of important tasks. As such, producing our own designer protein cages, complete with bespoke functionalities, is a promising avenue to new nanodevices, biotechnology and therapies. Herein, we describe how an artificial, computationally designed protein cage can be rationally engineered using supramolecular intuition to produce new functional capsules. Positive supercharging the interior cavity of this porous protein cage enables the efficient encapsulation of oligonucleotides by electrostatically-driven self-assembly. Moreover, the resulting cargo-loaded cages enter mammalian cells and release their cargo, for example siRNA which modulates gene expression. To expand the cargo scope of this proteinaceous container, a higher level of supramolecular complexity can also be introduced. Encapsulation of anionic surfactants affords protein-scaffolded micelles, which are capable of sequestering poorly water-soluble small molecules within their hydrophobic cores. These hybrid particles stably carry bioactive cargo and deliver it intracellularly, thereby increasing potency. Further development of these genetically-encoded materials is ongoing towards specific applications ranging from cell biology to medicine.

141 Translation and growth pathways are directly influenced by autoimmune regulator (Aire) in skin keratinocytes

Autoimmune regulator, Aire, is commonly known to function as a transcriptional regulator in medullary thymic epithelia. However, we and others have identified Aire to express and function in non-thymic tissues, including the skin, where it greatly influences inflammation and tumorigenesis. We report here that, within skin keratinocytes, Aire participates in a variety of cellular processes outside of its classically defined role in the nucleus. We employed a proximity based biotinylation screen (BioID) to examine the localization of Aire and its binding partners within keratinocytes. Aire is observed by structured illumination microscopy to localize in distinct subcellular compartments within the nucleus, cytoplasm, and along cytoskeletal tracks. Disease causing and function blocking mutations in Aire substantially alter these distribution patterns in keratinocytes, suggesting a link between Aire subcellular compartmentalization and pathogenesis. Using an isobaric labeling method (iTRAQ) coupled to tandem mass spectrometry, we identified 295 common Aire binding partners (99.0% probability), most of them novel, and quantitatively assessed the impact of Aire mutations on binding partner associations. Specifically, Aire binding partners associated with protein translation and cell growth (e.g. multiple 40S and 60S ribosomal protein subunits, cell growth-regulating nucleolar protein, eukaryotic translation initiation factors 4 and 5, elongation factor 1 alpha 1) were significantly altered in cells expressing mutant Aire compared to wild-type Aire. Serum pulse assays confirm a positive correlation between loss of wild-type Aire expression in keratinocytes and increased translation associated signaling (P-AKTS473, P-S6KT389, P-S6S235/S236, P-4EBP1S65, P-eIF4BS422, and P-eEF2KS366). These newly identified partners for Aire expand our understanding of Aire function in the skin and may provide a basis for the pro-tumorigenic role for Aire in skin cancers.

Promiscuous Binding of Microprotein Mozart1 to γ-Tubulin Complex Mediates Specific Subcellular Targeting to Control Microtubule Array Formation

How γ-tubulin ring complex (γ-TuRC), a master template for microtubule nucleation, is spatially and temporally regulated for the assembly of new microtubule arrays remains unclear. Here, we report that an evolutionarily conserved microprotein, Mozart1 (Mzt1), regulates subcellular targeting and microtubule formation activity of γ-TuRC at different cell cycle stages. Crystal structures of protein complexes demonstrate that Mzt1 promiscuously interacts with the N-terminal domains of multiple γ-tubulin complex protein subunits in γ-TuRC via an intercalative binding mode. Genetic- and microscopy-based analyses show that promiscuous binding of Mzt1 in γ-TuRC controls specific subcellular localization of γ-TuRC to modulate microtubule nucleation and stabilization in fission yeast. Moreover, we find Mzt1-independent targeting of γ-TuRC to be crucial for mitotic spindle assembly, demonstrating the cell-cycle-dependent regulation and function of γ-TuRC. Our findings reveal a microprotein-mediated regulatory mechanism underlying microtubule cytoskeleton formation, whereby Mzt1 binding promiscuity confers localization specificity on the multi-protein complex γ-TuRC.

Dissecting the Vesicular Trafficking Function of IFT Subunits.

Intraflagellar transport (IFT) was initially identified as a transport machine with multiple protein subunits, and it is essential for the assembly, disassembly, and maintenance of cilium/flagellum, which serves as the nexus of extracellular-to-intracellular signal integration. To date, in addition to its well-established and indispensable roles in ciliated cells, most IFT subunits have presented more general functions of vesicular trafficking in the non-ciliated cells. Thus, this review aims to summarize the recent progress on the vesicular trafficking functions of the IFT subunits and to highlight the issues that may arise in future research.

Exploring Molecular Descriptors and Fingerprints to Predict mTOR Kinase Inhibitors using Machine Learning Techniques.

Mammalian Target of Rapamycin (mTOR) is a Ser/Thr protein kinase, and its role is integral to the autophagy pathway in cancer. Targeting mTOR for therapeutic interventions in cancer through autophagy pathway is challenging due to the dual roles of autophagy in tumor progression. The architecture of mTOR reveals two complexes - mTORC1 and mTORC2, each having multiple protein subunits. mTOR kinase inhibitors target the structurally and functionally similar catalytic subunits of both mTORC1 and mTORC2. In this paper, we have explored two different categories of molecular features - descriptors and fingerprints for developing predictive models using machine learning techniques. Random Forest variable importance measures and autoencoders are used to identify molecular descriptors and fingerprints, respectively. We have built various predictive models using identified features and their combination for predicting mTOR kinase inhibitors. Finally, the best model based on the Mathew correlation co-efficient value over the validation dataset is selected for screening kinase SARfari bioactivity dataset. In this study, we have identified twenty best performing descriptors for predicting mTOR kinase inhibitors. To the best of our knowledge, it is the first study on integrating traditional machine learning and deep learning-based approaches for feature extraction to predict mTOR kinase inhibitors.

Controlled hierarchical self-assembly of networked coordination nanocapsules via the use of molecular chaperones.

Supramolecular chaperones play an important role in directing the assembly of multiple protein subunits and redox-active metal ions into precise, complex and functional quaternary structures. Here we report that hydroxyl tailed C-alkylpyrogallol[4]arene ligands and redox-active MnII ions, with the assistance of proline chaperone molecules, can assemble into two-dimensional (2D) and/or three-dimensional (3D) networked nanocapsules. Dimensionality is controlled by coordination between the exterior of nanocapsule subunits, and endohedral functionalization within the 2D system is achieved via chaperone guest encapsulation. The tailoring of surface properties of nanocapsules via coordination chemistry is also shown as an effective method for the fine-tuning magnetic properties, and electrochemical and spectroscopic studies support that the nanocapsule is an effective homogeneous water-oxidation electrocatalyst, operating at pH 6.07 with an exceptionally low overpotential of 368 mV.

Self-Assembly of Ferritin: Structure, Biological Function and Potential Applications in Nanotechnology.

Protein cages are normally formed by the self-assembly of multiple protein subunits and ferritin is a typical example of a protein cage structure. Ferritin is a ubiquitous multi-subunit iron storage protein formed by 24 polypeptide chains that self-assemble into a hollow, roughly spherical protein cage. Ferritin has external and internal diameters of approximately 12nm and 8nm, respectively. Functionally, ferritin performs iron sequestration and is highly conserved in evolution. The interior cavity of ferritin provides a unique reaction vessel to carry out reactions separated from the exterior environment. In nature, the cavity is utilized for sequestration of iron and bio-mineralization as a mechanism to render iron inert and safe from the external environment. Material scientists have been inspired by this system and exploited a range of ferritin superfamily proteins as supramolecular templates to encapsulate different carrier molecules ranging from cancer drugs to therapeutic proteins, in addition to using ferritin proteins as well-defined building blocks for fabrication. Besides the interior cavity, the exterior surface and sub-unit interface of ferritin can be modified without affecting ferritin assembly.

Bioengineering Strategies for Protein-Based Nanoparticles.

In recent years, the practical application of protein-based nanoparticles (PNPs) has expanded rapidly into areas like drug delivery, vaccine development, and biocatalysis. PNPs possess unique features that make them attractive as potential platforms for a variety of nanobiotechnological applications. They self-assemble from multiple protein subunits into hollow monodisperse structures; they are highly stable, biocompatible, and biodegradable; and their external components and encapsulation properties can be readily manipulated by chemical or genetic strategies. Moreover, their complex and perfect symmetry have motivated researchers to mimic their properties in order to create de novo protein assemblies. This review focuses on recent advances in the bioengineering and bioconjugation of PNPs and the implementation of synthetic biology concepts to exploit and enhance PNP’s intrinsic properties and to impart them with novel functionalities.