scholarly journals Using Self-Assembling Peptides to Integrate Biomolecules into Functional Supramolecular Biomaterials

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1450 ◽  
Author(s):  
Renjie Liu ◽  
Gregory A. Hudalla

Throughout nature, self-assembly gives rise to functional supramolecular biomaterials that can perform complex tasks with extraordinary efficiency and specificity. Inspired by these examples, self-assembly is increasingly used to fabricate synthetic supramolecular biomaterials for diverse applications in biomedicine and biotechnology. Peptides are particularly attractive as building blocks for these materials because they are based on naturally derived amino acids that are biocompatible and biodegradable; they can be synthesized using scalable and cost-effective methods, and their sequence can be tailored to encode formation of diverse architectures. To endow synthetic supramolecular biomaterials with functional capabilities, it is now commonplace to conjugate self-assembling building blocks to molecules having a desired functional property, such as selective recognition of a cell surface receptor or soluble protein, antigenicity, or enzymatic activity. This review surveys recent advances in using self-assembling peptides as handles to incorporate biologically active molecules into supramolecular biomaterials. Particular emphasis is placed on examples of functional nanofibers, nanovesicles, and other nano-scale structures that are fabricated by linking self-assembling peptides to proteins and carbohydrates. Collectively, this review highlights the enormous potential of these approaches to create supramolecular biomaterials with sophisticated functional capabilities that can be finely tuned to meet the needs of downstream applications.

2016 ◽  
Vol 22 (3) ◽  
pp. 309-315 ◽  
Author(s):  
Andreas Stengl ◽  
David Hörl ◽  
Heinrich Leonhardt ◽  
Jonas Helma

Monoclonal antibodies (mAbs) have become a central class of therapeutic agents in particular as antiproliferative compounds. Their often complex modes of action require sensitive assays during early, functional characterization. Current cell-based proliferation assays often detect metabolites that are indicative of metabolic activity but do not directly account for cell proliferation. Measuring DNA replication by incorporation of base analogues such as 5-bromo-2′-deoxyuridine (BrdU) fills this analytical gap but was previously restricted to bulk effect characterization in enzyme-linked immunosorbent assay formats. Here, we describe a cell-based assay format for the characterization of antiproliferative mAbs regarding potency and mode of action in a single experiment. The assay makes use of single cell–based high-content-analysis (HCA) for the reliable quantification of replicating cells and DNA content via 5-ethynyl-2′-deoxyuridine (EdU) and 4′,6-diamidino-2-phenylindole (DAPI), respectively, as sensitive measures of antiproliferative mAb activity. We used trastuzumab, an antiproliferative therapeutic antibody interfering with HER2 cell surface receptor-mediated growth signal transduction, and HER2-overexpressing cell lines BT474 and SKBR3 to demonstrate up to 10-fold signal-to-background (S/B) ratios for treated versus untreated cells and a shift in cell cycle profiles indicating antibody-induced cell cycle arrest. The assay is simple, cost-effective, and sensitive, providing a cell-based format for preclinical characterization of therapeutic mAbs.


2012 ◽  
Vol 9 (1) ◽  
pp. 43 ◽  
Author(s):  
Hueyling Tan

Molecular self-assembly is ubiquitous in nature and has emerged as a new approach to produce new materials in chemistry, engineering, nanotechnology, polymer science and materials. Molecular self-assembly has been attracting increasing interest from the scientific community in recent years due to its importance in understanding biology and a variety of diseases at the molecular level. In the last few years, considerable advances have been made in the use ofpeptides as building blocks to produce biological materials for wide range of applications, including fabricating novel supra-molecular structures and scaffolding for tissue repair. The study ofbiological self-assembly systems represents a significant advancement in molecular engineering and is a rapidly growing scientific and engineering field that crosses the boundaries ofexisting disciplines. Many self-assembling systems are rangefrom bi- andtri-block copolymers to DNA structures as well as simple and complex proteins andpeptides. The ultimate goal is to harness molecular self-assembly such that design andcontrol ofbottom-up processes is achieved thereby enabling exploitation of structures developed at the meso- and macro-scopic scale for the purposes oflife and non-life science applications. Such aspirations can be achievedthrough understanding thefundamental principles behind the selforganisation and self-synthesis processes exhibited by biological systems.


1979 ◽  
Vol 254 (9) ◽  
pp. 3194-3200
Author(s):  
A. Kulczycki ◽  
B L Hempstead ◽  
S L Hofmann ◽  
E W Wood ◽  
C W Parker

2002 ◽  
Vol 362 (2) ◽  
pp. 265-271 ◽  
Author(s):  
Manickavasagam SUNDARAM ◽  
Daan M. F. van AALTEN ◽  
John B. C. FINDLAY ◽  
Asipu SIVAPRASADARAO

Members of the lipocalin superfamily share a common structural fold, but differ from each other with respect to the molecules with which they interact. They all contain eight β-strands (A—H) that fold to form a well-defined β-barrel, which harbours a binding pocket for hydrophobic ligands. These strands are connected by loops that vary in size and structure and make up the closed and open ends of the pocket. In addition to binding ligands, some members of the family interact with other macromolecules, the specificity of which is thought to be associated with the variable loop regions. Here, we have investigated whether the macromolecular-recognition properties can be transferred from one member of the family to another. For this, we chose the prototypical lipocalin, the plasma retinol-binding protein (RBP) and its close structural homologue the epididymal retinoic acid-binding protein (ERABP). RBP exhibits three molecular-recognition properties: it binds to retinol, to transthyretin (TTR) and to a cell-surface receptor. ERABP binds retinoic acid, but whether it interacts with other macromolecules is not known. Here, we show that ERABP does not bind to TTR and the RBP receptor, but when the loops of RBP near the open end of the pocket (L-1, L-2 and L-3, connecting β-strands A—B, C—D and E—F, respectively) were substituted into the corresponding regions of ERABP, the resulting chimaera acquired the ability to bind TTR and the receptor. L-2 and L-3 were found to be the major determinants of the receptor- and TTR-binding specificities respectively. Thus we demonstrate that lipocalins serve as excellent scaffolds for engineering novel biological functions.


2021 ◽  
Author(s):  
Amine Driouchi ◽  
Scott Gray-Owen ◽  
Christopher M Yip

Mapping the self-organization and spatial distribution of membrane proteins is key to understanding their function. We report here on a correlated STORM/homoFRET imaging approach for resolving the nanoscale distribution and oligomeric state of membrane proteins. Live cell homoFRET imaging of CEACAM1, a cell-surface receptor known to exist in a complex equilibrium between monomer and dimer/oligomer states, revealed highly heterogenous diffraction-limited structures on the surface of HeLa cells. Correlated super-resolved STORM imaging revealed that these structures comprised a complex mixture and spatial distribution of self-associated CEACAM1 molecules. This correlated approach provides a compelling strategy for addressing challenging questions about the interplay between membrane protein concentration, distribution, interaction, clustering, and function.


2006 ◽  
Vol 14 (7S_Part_27) ◽  
pp. P1453-P1454
Author(s):  
Nicola J. Corbett ◽  
Kate Fisher ◽  
Helen A. Rowland ◽  
Alys C. Jones ◽  
Nigel M. Hooper

2008 ◽  
Vol 76 (7) ◽  
pp. 2862-2871 ◽  
Author(s):  
Xi Na ◽  
Ho Kim ◽  
Mary P. Moyer ◽  
Charalabos Pothoulakis ◽  
J. Thomas LaMont

ABSTRACT Clostridium difficile toxin A (TxA), a key mediator of antibiotic-associated colitis, requires binding to a cell surface receptor prior to internalization. Our aim was to identify novel plasma membrane TxA binding proteins on human colonocytes. TxA was coupled with biotin and cross-linked to the surface of HT29 human colonic epithelial cells. The main colonocyte binding protein for TxA was identified as glycoprotein 96 (gp96) by coimmunoprecipitation and mass spectrum analysis. gp96 is a member of the heat shock protein family, which is expressed on human colonocyte apical membranes as well as in the cytoplasm. TxA binding to gp96 was confirmed by fluorescence immunostaining and in vitro coimmunoprecipitation. Following TxA binding, the TxA-gp96 complex was translocated from the cell membrane to the cytoplasm. Pretreatment with gp96 antibody decreased TxA binding to colonocytes and inhibited TxA-induced cell rounding. Small interfering RNA directed against gp96 reduced gp96 expression and cytotoxicity in colonocytes. TxA-induced inflammatory signaling via p38 and apoptosis as measured by activation of BAK (Bcl-2 homologous antagonist/killer) and DNA fragmentation were decreased in gp96-deficient B cells. We conclude that human colonocyte gp96 serves as a plasma membrane binding protein that enhances cellular entry of TxA, participates in cellular signaling events in the inflammatory cascade, and facilitates cytotoxicity.


2008 ◽  
Vol 20 (9) ◽  
pp. 30
Author(s):  
M. Gamat ◽  
M. B. Renfree ◽  
A. J. Pask ◽  
G. Shaw

Androgens induce the differentiation of the urogenital sinus (UGS) to form a prostate. An early marker of this response is upregulation of the transcription factor Nkx3.1 in the urogenital epithelium in the precursors of prostatic buds. In tammars, prostate differentiation begins ~3 weeks after birth and after the time the testis starts to secrete androgens, and 2 weeks after androgen stimulated Wolffian duct differentiation. The reason for this delay in prostate differentiation is unexplained. Androgen receptors are present in the UGS, and the potent androgen, androstanediol, induces prostatic development in females. Whilst androgens may diffuse into cells by across the cell membrane, there is increasing evidence that steroids are also internalised actively via the cell-surface transport molecule Megalin. We are exploring the possibility that the delay may be related to the establishment of a Megalin-mediated pathway. Megalin is a cell surface receptor expressed on epithelia and mediates the endocytosis of a wide range of ligands, including SHBG-bound sex steroids. Megalin action is regulated by Receptor Associated Protein (RAP), which acts as an antagonist to Megalin action. This study cloned partial sequences of Megalin, RAP and Nkx3.1 and examined their expression in the developing urogenital sinus of the tammar wallaby using RT–PCR. The cellular distribution of Megalin protein in the developing UGS was examined using immunohistochemistry. Megalin, RAP and Nkx3.1 in the tammar were all highly conserved with eutherian orthologueues. Megalin and Nkx3.1 transcripts were detected in the liver, kidney, ovary, testis and developing urogenital sinus of male and female tammars. In the developing UGS of the tammar, there was strong staining for Megalin protein in the urogenital epithelium with some diffuse staining in the surrounding mesenchyme. Together, these results suggest that Megalin could be a key gene in the mediation of androgen action in prostatic development in the tammar wallaby.


Sign in / Sign up

Export Citation Format

Share Document