Collagen Sequence Research Articles

Collagen Sequence Analysis of the Extinct Giant Ground Sloths Lestodon and Megatherium.

For over 200 years, fossils of bizarre extinct creatures have been described from the Americas that have ranged from giant ground sloths to the ‘native’ South American ungulates, groups of mammals that evolved in relative isolation on South America. Ground sloths belong to the South American xenarthrans, a group with modern although morphologically and ecologically very different representatives (anteaters, armadillos and sloths), which has been proposed to be one of the four main eutherian clades. Recently, proteomics analyses of bone collagen have recently been used to yield a molecular phylogeny for a range of mammals including the unusual ‘Malagasy aardvark’ shown to be most closely related to the afrotherian tenrecs, and the south American ungulates supporting their morphological association with condylarths. However, proteomics results generate partial sequence information that could impact upon the phylogenetic placement that has not been appropriately tested. For comparison, this paper examines the phylogenetic potential of proteomics-based sequencing through the analysis of collagen extracted from two extinct giant ground sloths, Lestodon and Megatherium. The ground sloths were placed as sister taxa to extant sloths, but with a closer relationship between Lestodon and the extant sloths than the basal Megatherium. These results highlight that proteomics methods could yield plausible phylogenies that share similarities with other methods, but have the potential to be more useful in fossils beyond the limits of ancient DNA survival.

Dynamic Water-Mediated Hydrogen Bonding in a Collagen Model Peptide.

In the canonical (G-X-Y)(n) sequence of the fibrillar collagen triple helix, stabilizing direct interchain hydrogen bonding connects neighboring chains. Mutations of G can disrupt these interactions and are linked to connective tissue diseases. Here we integrate computational approaches with nuclear magnetic resonance (NMR) to obtain a dynamic view of hydrogen bonding distributions in the (POG)(4)(-)(POA)-(POG)(5) peptide, showing that the solution conformation, dynamics, and hydrogen bonding deviate from the reported X-ray crystal structure in many aspects. The simulations and NMR data provide clear evidence of inequivalent environments in the three chains. Molecular dynamics (MD) simulations indicate direct interchain hydrogen bonds in the leading chain, water bridges in the middle chain, and nonbridging waters in the trailing chain at the G → A substitution site. Theoretical calculations of NMR chemical shifts using a quantum fragmentation procedure can account for the unusual downfield NMR chemical shifts at the substitution sites and are used to assign the resonances to the individual chains. The NMR and MD data highlight the sensitivity of amide shifts to changes in the acceptor group from peptide carbonyls to water. The results are used to interpret solution NMR data for a variety of glycine substitutions and other sequence triplet interruptions to provide new connections between collagen sequences, their associated structures, dynamical behavior, and their ability to recognize collagen receptors.

Preserved Proteins from Extinct Bison latifrons Identified by Tandem Mass Spectrometry; Hydroxylysine Glycosides are a Common Feature of Ancient Collagen

Bone samples from several vertebrates were collected from the Ziegler Reservoir fossil site, in Snowmass Village, Colorado, and processed for proteomics analysis. The specimens come from Pleistocene megafauna Bison latifrons, dating back ∼ 120,000 years. Proteomics analysis using a simplified sample preparation procedure and tandem mass spectrometry (MS/MS) was applied to obtain protein identifications. Several bioinformatics resources were used to obtain peptide identifications based on sequence homology to extant species with annotated genomes. With the exception of soil sample controls, all samples resulted in confident peptide identifications that mapped to type I collagen. In addition, we analyzed a specimen from the extinct B. latifrons that yielded peptide identifications mapping to over 33 bovine proteins. Our analysis resulted in extensive fibrillar collagen sequence coverage, including the identification of posttranslational modifications. Hydroxylysine glucosylgalactosylation, a modification thought to be involved in collagen fiber formation and bone mineralization, was identified for the first time in an ancient protein dataset. Meta-analysis of data from other studies indicates that this modification may be common in well-preserved prehistoric samples. Additional peptide sequences from extracellular matrix (ECM) and non-ECM proteins have also been identified for the first time in ancient tissue samples. These data provide a framework for analyzing ancient protein signatures in well-preserved fossil specimens, while also contributing novel insights into the molecular basis of organic matter preservation. As such, this analysis has unearthed common posttranslational modifications of collagen that may assist in its preservation over time. The data are available via ProteomeXchange with identifier PXD001827.

Collagen-like peptide sequences inhibit bacterial invasion of root dentine.

To investigate the effects of peptides derived from the sequence of collagen to inhibit penetration of human or bovine dentine by species of streptococci and enterococci. Blocks of human or bovine root dentine were infected for 14days with bacterial cultures, in the presence or absence of various collagen-like peptide sequences. Invasion of dentinal tubules was determined from microscopic images of histochemically stained dentine thin sections. Extent of invasion was expressed as tubule invasion index (TI), or tubule invasion factor (TIF) which, in addition to the density of invasion, took into account the depth of invasion. Data were analysed by two-way anova. Streptococcus gordonii, Streptococcus mutans and Enterococcus faecalis were associated with heavy invasion (TI >2.5, TIF >4) of human or bovine root dentinal tubules, with E.faecalis being the most penetrative. Incorporation of peptides Gly-Pro-Ala or Gly-Pro-Hyp into the invitro model system significantly reduced (P<0.05) dentine invasion by the three species of highly invasive organisms. Inhibition of bacterial invasion by the peptides was dose dependent, and the peptides did not inhibit bacterial growth in culture. Specific collagen-like peptide sequences inhibited the invasion of dentine invitro by a range of oral bacteria. The peptides likely act as competitive inhibitors blocking bacterial collagen receptors and could potentially allow for target-specific control of dentine infections.

Biologically and diagenetically derived peptide modifications in moa collagens.

The modifications that occur on proteins in natural environments over time are not well studied, yet characterizing them is vital to correctly interpret sequence data recovered from fossils. The recently extinct moa (Dinornithidae) is an excellent candidate for investigating the preservation of proteins, their post-translational modifications (PTMs) and diagenetic alterations during degradation. Moa protein extracts were analysed using mass spectrometry, and peptides from collagen I, collagen II and collagen V were identified. We also identified biologically derived PTMs (i.e. methylation, di-methylation, alkylation, hydroxylation, fucosylation) on amino acids at locations consistent with extant proteins. In addition to these in vivo modifications, we detected novel modifications that are probably diagenetically derived. These include loss of hydroxylation/glutamic semialdehyde, carboxymethyllysine and peptide backbone cleavage, as well as previously noted deamidation. Moa collagen sequences and modifications provide a baseline by which to evaluate proteomic studies of other fossils, and a framework for defining the molecular relationship of moa to other closely related taxa.

Identification and Computational Analysis of Chicken Alpha-1 Collagen Sequences

Collagen is a protein that is found in cartilage, bone and other tissues in animals and humans. People utilize collagen from chicken for medicine. It is used to treat joint pain associated with many types of arthritis and surgery, with back pain, neck pain, and pain subsequent injury. So far, 26 genetically distinct collagen types have been described. However, there is not sufficient information to know if chicken collagen is safe or what the side effects might be. Other collagen products, such as bovine collagen and gelatin, have caused allergic reactions whereas chicken collagen has low amount of allergic reactions. It is recently found that collagen alpha-1 is involved in osteogenesis imperfecta phenotype in cattle, but there is no such type of information in case of chicken. So, attempting to figure out information about their structural features chicken alpha-1 collagen sequences are carried out and analyzed. This investigation reports a comparative analysis and characterization of the alpha-1 chain of chicken collagen sequences using different computational tools. Amino acid composition, physico-chemical, secondary structural, functional and phylogenetic classification were done, based on which, Alpha-1 (XIV) collagen, Collagen alpha-1(XIV) chain precursor and Collagen type XII alpha-1, which belong to the Fibril Associated Collagens with Interrupted Triple helices (FACIT) collagen family, can be recognized as potential players in diseased conditions, because of certain unusual properties such as very high aliphatic index, low percentage of Glycine and Proline residues and their proximity in evolutionary history. These collagen molecules might be play crucial role in cosmetics, foods on top of in medical industry.

A quantum chemical study of an interaction between collagen fragments and calcium ions using calculations of model complexes

Quantum chemical calculations revealed that the complexation between proline-containing collagen fragments and calcium ions involves a preferential interaction between Ca2+ ions and the oxygen and nitrogen atoms of proline in the glycine—proline—alanine fragment of the amino acid sequence of collagen.

Analysis of chronic low back pain with magnetic resonance imaging T2 mapping of lumbar intervertebral disc

BackgroundMagnetic resonance imaging (MRI) T2 mapping utilizes the T2 values for quantification of moisturecontent and collagen sequence breakdown. Recently, attempts at quantification of lumbar disc degeneration through MRI T2 mapping have been reported. We conducted an analysis of the relationship between T2 values of degenerated intervertebral discs (IVD) and chronic low back pain (CLBP). MethodsThe subjects who had CLBP comprised 28 patients (15 male, 13 female; mean age 48.9 ± 9.6 years; range 22–60 years). All subjects underwent MRI and filled out the low back pain visual analog scale (VAS) and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ). The disc was divided into the anterior annulus fibrosus (AF), the nucleus pulposus (NP), and the posterior AF, and each T2 value was measured. This study involved 25 asymptomatic control participants matched with the CLBP group subjects for gender and age (13 male, 12 female; mean age 43.8 ± 14.5 years; range 23–60 years). These subjects had no low back pain, and constituted the control group. ResultsT2 values for IVD tended to be lower in the CLBP group than in the control group, and these values were significantly different within the posterior AF. The correlation coefficients between the VAS scores and T2 values of anterior AF, NP and posterior AF were r = 0.30,−0.15 and −0.50. The correlation coefficient between the JOABPEQ scores (low back pain) and T2 values of anterior AF, NP and posterior AF were r = −0.0041, 0.11 and 0.42.Similarly, the JOABPEQ scores (lumbar function) were r = −0.22, −0.12 and 0.57. ConclusionsThe results indicated a correlation between posterior AF degeneration and CLBP. This study suggeststhat MRI T2 mapping could be used as a quantitative method for diagnosing discogenic pain.

The TrpA protein of Trichodesmium erythraeum IMS101 is a non-fibril-forming collagen and a component of the outer sheath.

Collagen molecules are structural in nature and primarily found in eukaryotic, multicellular organisms. Recently, a collagen-like protein, TrpA, was identified and characterized in the marine cyanobacterium Trichodesmium erythraeum IMS 101, and it was shown to be involved in maintaining the structural integrity of the trichomes. The TrpA protein contains one glycine interruption in the otherwise perfectly uninterrupted collagenous domain. In this study, we used phylogenetic analysis to determine that the TrpA protein sequence is most closely associated with non-fibril-forming collagen proteins. Structural modelling and circular dichroism data suggest that the glycine insertion decreases the stability of TrpA compared to uninterrupted collagen sequences. Additionally, scanning electron microscopy revealed that TrpA is expressed entirely on the surface of the trichomes, with no specific pattern of localization. These data indicate that the TrpA protein is part of the outer sheath of this organism. As such, this protein may function to promote adhesion between individual T. erythraeum trichomes, and between this organism and heterotrophic bacteria found in the same environment.

A first census of collagen interruptions: Collagen’s own stutters and stammers

The repetitive Gly-X-Y sequence is the telltale sign of triple helical domains in collagens and collagen-like proteins. Most collagen sequences contain sporadic interruptions of this pattern, which may have functional roles in molecular flexibility, assembly or molecular recognition. However, the structural signatures of the different interruptions are not well defined. Here, a first comprehensive survey of collagen interruptions on collagen sequences from different taxonomic groups is presented. Amino acid preferences at the sites of interruption and the flanking triplets are analysed separately for metazoan and prokaryotic collagens and the concept of commensurateness between interruptions is introduced. Known structural information from model peptides is used to present a common framework for hydrogen bonding topology and variations in superhelical twist for the different types of interruptions. Several collagen interruptions are further classified here as stutters or stammers in analogy to the heptad breaks observed in alpha-helical coiled coils, and the structural consequences of commensurate interruptions in heterotrimeric collagens are briefly discussed. Data presented here will be useful for further investigation on the relation between structure and function of collagen interruptions.

Faunal record identifies Bering isthmus conditions as constraint to end-Pleistocene migration to the New World.

Human colonization of the New World is generally believed to have entailed migrations from Siberia across the Bering isthmus. However, the limited archaeological record of these migrations means that details of the timing, cause and rate remain cryptic. Here, we have used a combination of ancient DNA, 14C dating, hydrogen and oxygen isotopes, and collagen sequencing to explore the colonization history of one of the few other large mammals to have successfully migrated into the Americas at this time: the North American elk (Cervus elaphus canadensis), also known as wapiti. We identify a long-term occupation of northeast Siberia, far beyond the species's current Old World distribution. Migration into North America occurred at the end of the last glaciation, while the northeast Siberian source population became extinct only within the last 500 years. This finding is congruent with a similar proposed delay in human colonization, inferred from modern human mitochondrial DNA, and suggestions that the Bering isthmus was not traversable during parts of the Late Pleistocene. Our data imply a fundamental constraint in crossing Beringia, placing limits on the age and mode of human settlement in the Americas, and further establish the utility of ancient DNA in palaeontological investigations of species histories.

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. Chimeric collagens were generated by inserting the putative fibronectin-binding region from human collagen into the bacterial collagen sequence. Insertion of a sufficient length of human sequence conferred fibronectin affinity. The minimum sequence requirement was identified as a 6-triplet sequence near the unique collagenase cleavage site and was the same in both triple-helix and denatured states. Denaturation of the chimeric collagen increased its affinity for fibronectin, as seen for mammalian collagens. The fibronectin binding recombinant collagen did not contain hydroxyproline, indicating hydroxyproline is not essential for binding. However, its absence may account, in part, for the higher affinity of the native chimeric protein and the lower affinity of the denatured protein compared with type II collagen. Megakaryocytes cultured on chimeric collagen with fibronectin affinity showed improved adhesion and differentiation, suggesting a strategy for generating bioactive materials in biomedical applications.

Circular Permutation Directs Orthogonal Assembly in Complex Collagen Peptide Mixtures

Multiple types of natural collagens specifically assemble and co-exist in the extracellular matrix. Although noncollagenous trimerization domains facilitate the folding of triple-helical regions, it is intriguing to ask whether collagen sequences are also capable of controlling heterospecific association. In this study, we designed a model system mimicking simultaneous specific assembly of two collagen heterotrimers using a genetically inspired operation, circular permutation. Previously, surface charge-pair interactions were optimized on three collagen peptides to promote the formation of an abc-type heterotrimer. Circular permutation of these sequences retained networks of stabilizing interactions, preserving both triple-helical structure and heterospecificity of assembly. Combining original peptides A, B, and C and permuted peptides D, E, and F resulted primarily in formation of A:B:C and D:E:F, a heterospecificity of 2 of 56 possible stoichiometries. This degree of specificity in collagen molecular recognition is unprecedented in natural or synthetic collagens. Analysis of natural collagen sequences indicates low similarity between the neighboring exons. Combining the synthetic collagen model and bioinformatic analysis provides insight on how fibrillar collagens might have arisen from the duplication of smaller domains.

Identification of Bilirubin Binding Site in Type I Collagen

The interaction of bilirubin with collagen in the significance of jaundice incidence have been previously reported and investigated. The novel peptide sequences containing bilirubin binding domain was identified and located to develop a basis for further studies investigating the interactions of collagen with bilirubin in the present study. In this study an intricate interaction between bilirubin and collagen was characterized and their binding domain has been established using in-gel digestion and LC–MS/MS analysis based on the collagen sequencing and peptide mass fingerprinting. The biotinylated bilirubin derivatives bind to α1(I) chain but not to α2(I) chains which clearly designates that bilirubin shows greater affinity to α1 chains of collagen. The intact proteins collected after analyzing the resulting complex mixture of peptides was used for peptide mapping. Using the electrospray method, among the other peptide sequence information obtained, the molecular weight of collagen alpha-2(I) chain was obtained by locating a 130 kDa weight peptide sequences with greater pi value (9.14) with 1,364 amino acid residues and collagen alpha-1(I) chain with 1,463 amino acid residues with 138.9 kDa molecular weight. This information leads to locate the exact sequence of these helices focussing on the domain identification. The total charge of the peptide domain sequences infers that the bilirubin participates in the electrostatic mode of interaction with collagen peptide. Moreover, other modes of interactions such as hydrogen bonding, covalent interactions and hydrophobic interactions are possible.

Crystal structure of the collagen model peptide (Pro-Pro-Gly)4-Hyp-Asp-Gly-(Pro-Pro-Gly)4at 1.0 Å resolution

The single-crystal structure of the collagen-like peptide (Pro-Pro-Gly)4 -Hyp-Asp-Gly-(Pro-Pro-Gly)4, was analyzed at 1.02 Å resolution. The overall average helical twist (θ = 49.6°) suggests that this peptide adopts a 7/2 triple-helical structure and that its conformation is very similar to that of (Gly-Pro-Hyp)9, which has the typical repeating sequence in collagen. High-resolution studies on other collagen-like peptides have shown that imino acid-rich sequences preferentially adopt a 7/2 triple-helical structure (θ = 51.4°), whereas imino acid-lean sequences adopt relaxed conformations (θ < 51.4°). The guest Gly-Hyp-Asp sequence in the present peptide, however, has a large helical twist (θ = 61.1°), whereas that of the host Pro-Pro-Gly sequence is small (θ = 46.7°), indicating that the relationship between the helical conformation and the amino acid sequence of such peptides is complex. In the present structure, a strong intermolecular hydrogen bond between two Asp residues on the A and B strands might induce the large helical twist of the guest sequence; this is compensated by a reduced helical twist in the host, so that an overall 7/2-helical symmetry is maintained. The Asp residue in the C strand might interact electrostatically with the N-terminus of an adjacent molecule, causing axial displacement, reminiscent of the D-staggered structure in fibrous collagens.

Site-specific Quantitative Analysis of Overglycosylation of Collagen in Osteogenesis Imperfecta Using Hydrazide Chemistry and SILAC

We recently developed a novel method for analysis of collagen O-glycosylations, which include galactosyl-hydroxylysine (GHL) and glucosyl-galactosyl-hydroxylysine (GGHL), using hydrazide chemistry (Taga, Y., Mol. Cell. Proteomics 2012, 11 (6), M111.010397). Here we investigated an overglycosylation model of collagen produced by cultured skin fibroblasts from osteogenesis imperfecta (OI) patients using this method. Many GHL/GGHL sites were identified in normal and OI type I collagens by LC-MS analysis after the glycopeptide purification procedure. Further, relative quantification was performed on each identified glycopeptide using stable isotope labeling by amino acids in cell culture (SILAC). Significant increases of GGHL were observed at respective glycosylation sites of type I collagen in OI, whereas an OI-specific glycosylation site was not found. These results demonstrated that the overglycosylation of type I collagen proceeds only at specific sites, resulting in accumulation of GGHL, rather than because of an increase of nonspecific glycosylation. Although the roles of collagen O-glycosylations in OI and even in normal conditions are still incompletely understood, the location of GHL/GGHL in the collagen sequence is suggested to be important for their functions.

A Molecular Phylogeny of Plesiorycteropus Reassigns the Extinct Mammalian Order ‘Bibymalagasia’

Madagascar is well known for its diverse fauna and flora, being home to many species not found anywhere else in the world. However, its biodiversity in the recent past included a range of extinct enigmatic fauna, such as elephant birds, giant lemurs and dwarfed hippopotami. The ‘Malagasy aardvark’ (Plesiorycteropus) has remained one of Madagascar’s least well-understood extinct species since its discovery in the 19th century. Initially considered a close relative of the aardvark (Orycteropus) within the order Tubulidentata, more recent morphological analyses challenged this placement on the grounds that the identifiably derived traits supporting this allocation were adaptations to digging rather than shared ancestry. Because the skeletal evidence showed many morphological traits diagnostic of different eutherian mammal orders, they could not be used to resolve its closest relatives. As a result, the genus was tentatively assigned its own taxonomic order ‘Bibymalagasia’, yet how this order relates to other eutherian mammal orders remains unclear despite numerous morphological investigations. This research presents the first known molecular sequence data for Plesiorycteropus, obtained from the bone protein collagen (I), which places the ‘Malagasy aardvark’ as more closely related to tenrecs than aardvarks. More specifically, Plesiorycteropus was recovered within the order Tenrecoidea (golden moles and tenrecs) within Afrotheria, suggesting that the taxonomic order ‘Bibymalagasia’ is obsolete. This research highlights the potential for collagen sequencing in investigating the phylogeny of extinct species as a viable alternative to ancient DNA (aDNA) sequencing, particularly in cases where aDNA cannot be recovered.

Computational analysis of bovine alpha-1 collagen sequences.

Bovine collagen alpha-1 is a naturally occurring extracellular matrix protein found in tendons and other connective tissues. It plays a vital role in cell growth, differentiation, attachment, and migration. Recent findings have established that collagen alpha-1 is involved in osteogenesis imperfecta phenotype in cattle but deep information about other members of this large family is not available so far. So with a view to finding a new edge and attempt to figure out a correlation among the well attributed Bovine alpha-1 collagen sequences are executed and analyzed. To do so, comparative analysis among the 28 members of collagen family has been carried out using Computational tools. Consequently, based on the physico-chemical, secondary structural, functional and phylogenetic classifications, we have selected collagen 12, 14 and 20 as targets for pathological conditions. These proteins belong to the FACIT family and significantly showed low glycine and proline content, high instability and aliphatic index. Moreover, FACIT family collagens contain multiple triple helical domains and being members of the FACIT family, bovine collagen 12, 14, 20 do not form fibrils by themselves but they are associated to collagen 1 associated fibrils. These collagen molecules might be crucial candidates to detect and understand the process of matrix remodeling in diseases especially in the arena of cellular compartments.

Discoidin Domain Receptors Promote α1β1- and α2β1-Integrin Mediated Cell Adhesion to Collagen by Enhancing Integrin Activation

The discoidin domain receptors, DDR1 and DDR2, are receptor tyrosine kinases that bind to and are activated by collagens. Similar to collagen-binding β1 integrins, the DDRs bind to specific motifs within the collagen triple helix. However, these two types of collagen receptors recognize distinct collagen sequences. While GVMGFO (O is hydroxyproline) functions as a major DDR binding motif in fibrillar collagens, integrins bind to sequences containing Gxx’GEx”. The DDRs are thought to regulate cell adhesion, but their roles have hitherto only been studied indirectly. In this study we used synthetic triple-helical collagen-derived peptides that incorporate either the DDR-selective GVMGFO motif or integrin-selective motifs, such as GxOGER and GLOGEN, in order to selectively target either type of receptor and resolve their contributions to cell adhesion. Our data using HEK293 cells show that while cell adhesion to collagen I was completely inhibited by anti-integrin blocking antibodies, the DDRs could mediate cell attachment to the GVMGFO motif in an integrin-independent manner. Cell binding to GVMGFO was independent of DDR receptor signalling and occurred with limited cell spreading, indicating that the DDRs do not mediate firm adhesion. However, blocking the interaction of DDR-expressing cells with collagen I via the GVMGFO site diminished cell adhesion, suggesting that the DDRs positively modulate integrin-mediated cell adhesion. Indeed, overexpression of the DDRs or activation of the DDRs by the GVMGFO ligand promoted α1β1 and α2β1 integrin-mediated cell adhesion to medium- and low-affinity integrin ligands without regulating the cell surface expression levels of α1β1 or α2β1. Our data thus demonstrate an adhesion-promoting role of the DDRs, whereby overexpression and/or activation of the DDRs leads to enhanced integrin-mediated cell adhesion as a result of higher integrin activation state.

Multiscale characterization of a chimeric biomimetic polypeptide for stem cell culture

Mesenchymal stem cells have attracted great interest in the field of tissue engineering and regenerative medicine because of their multipotentiality and relative ease of isolation from adult tissues. The medical application of this cellular system requires the inclusion in a growth and delivery scaffold that is crucial for the clinical effectiveness of the therapy. In particular, the ideal scaffolding material should have the needed porosity and mechanical strength to allow a good integration with the surrounding tissues, but it should also assure high biocompatibility and full resorbability. For such a purpose, protein-inspired biomaterials and, in particular, elastomeric-derived polypeptides are playing a major role, in which they are expected to fulfil many of the biological and mechanical requirements. A specific chimeric protein, designed starting from elastin, resilin and collagen sequences, was characterized over different length scales. Single-molecule mechanics, aggregation properties and compatibility with human mesenchymal stem cells were tested, showing that the engineered compound is a good candidate as a stem cell scaffold to be used in tissue engineering applications.