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G B Fields

Publications and source records attributed to G B Fields.

At least 19 recordsLinked to original sources
PubMed1999

Structure and dynamics of peptide-amphiphiles incorporating triple-helical proteinlike molecular architecture.

Organized polymeric assemblies that incorporate bioactive sequences and structures are finding important applications for the study of protein structure-function relationships. We have recently described a heteropolymeric peptide-amphiphile system that forms organized structures in solution and on surfaces. While the overall three-dimensional features of peptide-amphiphiles have been studied previously, the precise environment of specific residues, particularly those within biologically active regions, have not been examined in detail. In the present study, we have used heteronuclear single quantum coherence (HSQC) and inverse-detected 1H-15N NMR spectroscopy to examine the structure and dynamics of a peptide and peptide-amphiphile that incorporate the alpha1(IV)1263-1277 ([IV-H1]) amino acid sequence from type IV collagen. Three variants of the sequence (Gly-Pro-Hyp)4-[IV-H1]-(Gly-Pro-Hyp)4 were constructed with a single 15N-labeled Gly placed in the middle of the N-terminal (Gly-Pro-Hyp)4 region (residue Gly7), in the middle of the [IV-H1] sequence (residue Gly19), or in the middle of the C-terminal (Gly-Pro-Hyp)4 region (residue Gly34). These peptides were also N-terminally acylated with hexanoic acid to create an analogous series of 15N-labeled peptide-amphiphiles. HSQC spectra indicated that both the peptide and the peptide-amphiphile were in triple-helical conformation at low temperature, supporting prior circular dichroism (CD) spectroscopic results. The intensities of the triple-helical cross-peaks were stronger for the peptide-amphiphile, consistent with an enhanced triple-helical thermal stability within the peptide-amphiphile construct compared to that of the peptide alone. Relative relaxation values for the peptide-amphiphile monomeric and trimeric species were consistent with those reported previously for other triple-helical peptides. Relaxation measurements indicated that the triple-helical [IV-H1] region did not appear to be dramatically more flexible than the Gly-Pro-Hyp regions. The angle between Gly N-H bonds and the helix dyad axis, determined from the relaxation data, was within the range expected for triple helices. Overall, the peptide headgroup of the C6-(Gly-Pro-Hyp)4-[IV-H1]-(Gly-Pro-Hyp)4 peptide-amphiphile appears to form a continuous triple helix that behaves similarly, in a dynamic sense, to a triple-helical peptide. The enhanced thermal stability of the peptide-amphiphile compared to the analogous triple-helical peptide, along with the multitude of organized structures formed by lipidlike compounds, suggest that peptide-amphiphiles could be utilized as targeted liposomes, sensors, receptors, or enzymes.

Amino Acid Sequence↗
PubMed1999

Cellular recognition of synthetic peptide amphiphiles in self-assembled monolayer films.

The incorporation of lipidated cell adhesion peptides into self-assembled structures such as films provides the opportunity to develop unique biomimetic materials with well-organized interfaces. Synthetic dialkyl tails have been linked to the amino-terminus, carboxyl-terminus, and both termini of the cell recognition sequence Arg-Gly-Asp (RGD) to produce amino-coupled, carboxyl-coupled, and looped RGD peptide amphiphiles. All three amphiphilic RGD versions self-assembled into fairly stable mixed monolayers that deposited well as Langmuir-Blodgett films on surfaces, except for films containing amino-coupled RGD amphiphiles at high peptide concentrations. FT-IR studies showed that amino-coupled RGD head groups formed the strongest lateral hydrogen bonds. Melanoma cells spread on looped RGD amphiphiles in a concentration-dependent manner, spread indiscriminately on carboxyl-coupled RGD amphiphiles, and did not spread on amino-coupled RGD amphiphiles. Looped RGD amphiphiles promoted the adhesion, spreading, and cytoskeletal reorganization of melanoma and endothelial cells while control looped Arg-Gly-Glu (RGE) amphiphiles inhibited them. Antibody inhibition of the integrin receptor alpha3beta1 blocked melanoma cell adhesion to looped RGD amphiphiles. These results confirm that novel biomolecular materials containing synthetic peptide amphiphiles have the potential to control cellular behavior in a specific manner.

Actins↗
PubMed1999

Induction of protein-like molecular architecture by self-assembly processes.

One of the most intriguing self-assembly processes is the folding of peptide chains into native protein structures. We have developed a method for building protein-like structural motifs that incorporate sequences of biological interest. A lipophilic moiety is attached onto an N(alpha)-amino group of a peptide chain, resulting in a 'peptide-amphiphile'. The alignment of amphiphilic compounds at the lipid solvent interface is used to facilitate peptide alignment and structure initiation and propagation. Peptide-amphiphiles containing potentially triple-helical structural motifs have been synthesized. The resultant head group structures have been characterized by circular dichroism and NMR spectroscopies. Evidence for a self-assembly process of peptide-amphiphiles has been obtained from: (a) circular dichroism spectra and melting curves characteristic of triple-helices, (b) one- and two-dimensional NMR spectra indicative of stable triple-helical structure at low temperatures and melted triple-helices at high temperatures, and (c) pulsed-field gradient NMR experiments demonstrating different self-diffusion coefficients between proposed triple-helical and non-triple-helical species. The peptide-amphiphiles described here provide a simple approach for building stable protein structural motifs using peptide head groups.

Circular Dichroism↗
PubMed1998

Defining the domains of type I collagen involved in heparin- binding and endothelial tube formation.

Cell surface heparan sulfate proteoglycan (HSPG) interactions with type I collagen may be a ubiquitous cell adhesion mechanism. However, the HSPG binding sites on type I collagen are unknown. Previously we mapped heparin binding to the vicinity of the type I collagen N terminus by electron microscopy. The present study has identified type I collagen sequences used for heparin binding and endothelial cell-collagen interactions. Using affinity coelectrophoresis, we found heparin to bind as follows: to type I collagen with high affinity (Kd approximately 150 nM); triple-helical peptides (THPs) including the basic N-terminal sequence alpha1(I)87-92, KGHRGF, with intermediate affinities (Kd approximately 2 microM); and THPs including other collagenous sequences, or single-stranded sequences, negligibly (Kd >> 10 microM). Thus, heparin-type I collagen binding likely relies on an N-terminal basic triple-helical domain represented once within each monomer, and at multiple sites within fibrils. We next defined the features of type I collagen necessary for angiogenesis in a system in which type I collagen and heparin rapidly induce endothelial tube formation in vitro. When peptides, denatured or monomeric type I collagen, or type V collagen was substituted for type I collagen, no tubes formed. However, when peptides and type I collagen were tested together, only the most heparin-avid THPs inhibited tube formation, likely by influencing cell interactions with collagen-heparin complexes. Thus, induction of endothelial tube morphogenesis by type I collagen may depend upon its triple-helical and fibrillar conformations and on the N-terminal heparin-binding site identified here.

Amino Acid Sequence↗
PubMed1998

Interactions of type IV collagen and its domains with human mesangial cells.

Type IV collagen (COL-IV) interacts with a variety of cell types. We present evidence that human mesangial cells (HMC) bind directly to COL-IV, its major triple helical domain, and the main non-collagenous, NC1 domain. A synthetic peptide, HEP-III, and its triple helical counterpart (THP-III), previously reported to be a heparin-binding domain, also promoted approximately 15% adhesion of HMC. HMC bound to solid-phase-immobilized, intact COL-IV (approximately 75%), isolated NC1 domain (approximately 15%), and a pepsin-derived triple helical fragment,which lacks Hep-III (approximately 65%). We further examined inhibition of HMC adhesion to COL-IV and its domains by using anti-integrin antibodies. Blocking monoclonal antibodies against the alpha2 integrin resulted in 70% inhibition of adhesion to COL-IV and 80% inhibition to HEP-III. Moderate inhibition was observed on the NC1 and triple helical fragments. Anti-alpha1 antibodies inhibited the binding of HMC to COL-IV, the NC1, and triple helical domains, but not to peptide HEP-III. Anti-beta1 antibodies inhibited almost completely (>95%) the adhesion to COL-IV, the NC1, and triple helical fragments; inhibition on HEP-III was approximately 30%. Affinity chromatography studies with solid-phase HEP-III and mesangial cell lysate also demonstrated the presence of integrin alpha2 beta1 along with alpha3 beta1. We conclude that alpha2 beta1 and alpha1 beta1 integrins mediate HMC adhesion to COL-IV. Peptide HEP-III is a major, specific site for alpha2 integrin-mediated binding of mesangial cells to COL-IV. Both the alpha1 beta1 and alpha2 beta1 integrins interact with the NC1 and triple helical fragments of COL-IV. Therefore, we demonstrate that several sites for integrin-mediated interactions exist on several collagenous and non-collagenous domains of COL-IV.

Antibodies, Monoclonal↗
PubMed1998

Effect of ligand conformation on melanoma cell alpha3beta1 integrin-mediated signal transduction events: implications for a collagen structural modulation mechanism of tumor cell invasion.

The importance of three-dimensional interactions between receptors with their respective ligands has been extensively explored during the binding process, but considerably less so for postbinding events such as induction of signaling pathways. Tumor cell receptor association with basement membrane proteins is believed to facilitate the metastatic process. Melanoma and ovarian carcinoma cells have been shown to utilize the alpha3beta1 integrin to bind to models of the alpha1(IV)531-543 sequence from basement membrane (type IV) collagen [Miles, A. J., et al. (1994) J. Biol. Chem. 269, 30939-30945; Miles, A. J., et al. (1995) J. Biol. Chem. 270, 29047-29050]. In the present study, the effects of ligand three-dimensional structure on possible signal transduction pathways induced by alpha3beta1 integrin binding have been evaluated. Human melanoma cell binding to type IV collagen resulted in Tyr phosphorylation of p125(FAK), consistent with prior studies correlating beta1 integrin subunit binding to collagen and p125(FAK) Tyr phosphorylation. Cross-linking of an anti-alpha3 integrin subunit monoclonal antibody also induced p125(FAK) Tyr phosphorylation. Incubation of melanoma cells with single-stranded or triple-helical peptide models of alpha1(IV)531-543 induced Tyr phosphorylation of intracellular proteins. Immunoprecipitation analysis identified one of these proteins as pp125(FAK). Induction of p125(FAK) Tyr phosphorylation was enhanced and the time of induction was shortened when the ligand was used in triple-helical conformation. Subsequent clustering of either the single-stranded or the triple-helical ligand also increased the level of p125(FAK) phosphorylation compared to unclustered ligand. The clustered triple-helical peptide ligand induced more rapid paxillin Tyr phosphorylation than the single-stranded ligand. In addition, the induction of activated proteases was found to be more rapid due to ligand triple helicity. Overall, these studies have shown that (i) a model of an isolated sequence from type IV collagen, alpha1(IV)531-543, can induce alpha3beta1 integrin-mediated signal transduction in melanoma cells and (ii) ligand conformation (secondary, tertiary, and/or quaternary structure) can directly influence several alpha3beta1 integrin-mediated signal transduction events. The effects of ligand conformation suggest that a "collagen structural modulation" mechanism may exist for tumor cell invasion, whereby triple-helical collagen promotes cell binding and induction of signal transduction, subsequently leading to collagen dissolution by proteases, decreased signal transduction, and enhanced tumor cell motility.

Cell Adhesion↗
PubMed1998

Protein-like molecular architecture: biomaterial applications for inducing cellular receptor binding and signal transduction.

The development of biomaterials with desirable biocompatibility has presented a difficult challenge for tissue engineering researchers. First and foremost, materials themselves tend to be hydrophobic and/or thrombogenic in nature, and face compatibility problems upon implantation. To mediate this problem, researchers have attempted to graft protein fragments onto biomaterial surfaces to promote endothelial cell attachment and minimize thrombosis. We envisioned a novel approach, based on the capability of biomolecules to self-assemble into well-defined and intricate structures, for creating biomimetic biomaterials that promote cell adhesion and proliferation. One of the most intriguing self-assembly processes is the folding of peptide chains into native protein structures. We have developed a method for building protein-like structural motifs that incorporate sequences of biological interest. A lipophilic moiety is attached onto a N alpha-amino group of peptide chain, resulting in a "peptide-amphiphile." The alignment of amphiphilic compounds at the lipid-solvent interface is used to facilitate peptide alignment and structure initiation and propagation, while the lipophilic region absorbs to hydrophobic surfaces. Peptide-amphiphiles containing potentially triple-helical or alpha-helical structural motifs have been synthesized. The resultant head group structures have been characterized by CD spectroscopy and found to be thermally stable over physiological temperature ranges. Triple-helical peptide-amphiphiles have been applied to studies of surface modification and cell receptor binding. Cell adhesion and spreading was promoted by triple-helical peptide-amphiphiles. Cellular interaction with the type IV collagen sequence alpha 1(IV) 1263-1277 increased signal transduction, with both the time and level of induction dependent upon triple-helical conformation. Collectively, these results suggest that peptide-amphiphiles may be used to form stable molecular structure on biomaterial surfaces that promote cellular activities and improve biocompatibility.

Amino Acid Sequence↗
PubMed1997

An all-D amino acid peptide model of alpha1(IV)531-543 from type IV collagen binds the alpha3beta1 integrin and mediates tumor cell adhesion, spreading, and motility.

Type IV collagen promotes integrin-mediated cell adhesion, spreading, and motility. Several regions within the triple-helical domain of type IV collagen have been identified as tumor cellular recognition sites. Among these regions, the alpha1(IV)531-543 sequence, designated L-Hep-III, promotes integrin-mediated tumor cell adhesion and directly binds to the alpha3beta1 integrin [Miles, A. J., et al. (1994) J. Biol. Chem. 269, 30939-30945; Miles, A. J., et al. (1995) J. Biol. Chem. 270, 29047-29050]. We have presently compared the activities of the all-d enantiomeric peptide model of alpha1(IV)531-543, designated D-Hep-III, with L-Hep-III, for promoting the adhesion, spreading, and motility of metastatic melanoma and breast carcinoma cells. D-Hep-III was found to support melanoma and breast carcinoma cell adhesion, spreading, and motility in a dose-dependent fashion similar to that of L-Hep-III. The adhesions of melanoma and breast carcinoma cells to both type IV collagen and fibronectin were effectively inhibited by L-Hep-III and D-Hep-III. Melanoma cell invasion of the basement membrane was also inhibited by D-Hep-III. Characterization of the cell surface receptor for D-Hep-III was acheived via cell adhesion assays and affinity chromatography using monoclonal antibodies against integrin subunits. Immunoprecipitation analysis following EDTA elution from a D-Hep-III affinity column indicated that D-Hep-III binds to the alpha3beta1 integrin but not to the alpha2 or alpha6 integrin subunits. In summary, these studies demonstrate that an all-D model of the alpha1(IV)531-543 sequence mimics the biological activities of the all-L peptide. D-Hep-III is the first all-D peptide that has been shown to promote tumor cell adhesion, spreading, and migration, inhibit tumor cell adhesion and migration on type IV collagen and invasion of the basement membrane, and bind directly to an integrin. Due to the resistance to proteolysis, all-D receptor-binding peptides such as D-Hep-III have great potential for in vivo studies and as therapeutic agents.

Antibodies, Monoclonal↗
PubMed1997

Inhibition of melanoma cell binding to type IV collagen by analogs of cell adhesion regulator.

Integrin-mediated tumor cell adhesion to type IV collagen is believed to play a role in the invasion of basement membrane proteins and the subsequent metastatic process. The cellular protein CAR (cell adhesion regulator) has been proposed to influence integrin-mediated binding to extracellular matrix proteins, including basement membrane (type IV) collagen. Three analogs of the CAR138-142 have been tested for activity. The first contains the 138-142 sequence (CAR138-142, Val-Glu-Ile-Leu-Tyr-NH2), the second contains the 138-142 sequence with a phosphorylated Tyr [pCAR138-142, Val-Glu-Ile-Leu-Tyr(PO3H2)-NH2], and the third contains the reversed 138-142 sequence (rCAR138-142, Tyr-Leu-Ile-Glu-Val-NH2). When added extracellularly, none of the analogs had a significant affect on cell adhesion to type IV collagen. Using a novel reversible cell permeabilization method, we found that intracellular incorporation of both CAR138-142 and pCAR138-142 resulted in inhibition of cell adhesion in a dose-dependent fashion. The IC50 values were approximately 90 and approximately 10 microM for CAR138-142 and pCAR138-142, respectively. Intracellular incorporation of the rCAR138-142 peptide had no affect on cell adhesion. Fluorescence microscopy of a fluorescein-labeled CAR138-142 peptide revealed that the reversible permeabilization procedure resulted in the peptides crossing the cell membrane. Affinity chromatography of melanoma cell lysates with pCAR138-142 or rCAR138-142 attached to a solid support of magnetic beads suggested that one protein was bound uniquely by pCAR138-142. Immunoprecipitation analysis identified vinculin, a protein associated with the actin cytoskeleton, as the protein specifically bound by pCAR138-142. Immunoprecipitation with pp125FAK- or beta 1-integrin-derived mAbs gave negative results. Our study suggests that a possible therapeutic approach for inhibition of melanoma cell adhesion adhesion to extracellular matrix proteins is the use of CAR peptide analogs intracellularly.

ATPases Associated with Diverse Cellular Activitie↗
PubMed1997

CD7-mediated regulation of integrin adhesiveness on human T cells involves tyrosine phosphorylation-dependent activation of phosphatidylinositol 3-kinase.

The functional activity of integrin receptors on T cells is dynamically regulated so that T cells can alternate rapidly between adhesive and nonadhesive states. The CD7 Ag is one of several molecules on T cells that can transduce intracellular signals that rapidly up-regulate integrin-mediated adhesion. We demonstrate in this report that the signaling pathway that CD7 utilizes to regulate integrin activity involves the lipid kinase phosphatidylinositol 3-kinase (PI 3-K). CD7 stimulation of both Jurkat T cells and resting human peripheral blood CD4+ T cells results in rapid association and activation of PI 3-K with CD7. Phosphopeptide competition assays demonstrate that the association of CD7 with PI 3-K is dependent on tyrosine phosphorylation of the SH2 binding motif Tyr-Glu-Asp-Met (YEDM) in the CD7 cytoplasmic domain. A role for PI 3-K in the regulation of integrin function by CD7 is demonstrated by: 1) the ability of two structurally distinct PI 3-K inhibitors, wortmannin and LY294002, to inhibit CD7-mediated increases in beta1 integrin function of human T cells; and 2) inhibition of CD7-mediated activation of beta3 integrin function in human T cells by expression of a dominant negative form of the p85 subunit of PI 3-K. These results demonstrate that the CD7 Ag on human T cells is coupled to PI 3-K and that this association is relevant to CD7-mediated signaling events, specifically CD7-induced increases in integrin adhesiveness. Furthermore, these studies provide important new evidence implicating PI 3-K in the regulation of integrin adhesiveness by multiple cell surface signaling receptors.

Antigens, CD7↗
PubMed1997

Backbone and side-chain dynamics of residues in a partially folded beta-sheet peptide from platelet factor-4.

Structurally characterizing partially folded states is problematic given the nature of these transient species. A peptide 20mer, T38AQLIATLKNGRKISLDLQA57 (P20), which has been shown to partially fold in a relatively stable turn/loop conformation (LKNGR) and transient beta-sheet structure, is a good model for studying backbone and side-chain mobilities in a transiently folded peptide by using 13C-NMR relaxation. Here, four residues in P20, A43, T44, G48, and 151, chosen for their positions in or near the loop conformation and for compositional variety, have been selectively 13C-enriched. Proton-coupled and decoupled 13C-NMR relaxation experiments have been performed to obtain the temperature dependencies (278 K to 343 K) of auto- and cross-correlation motional order parameters and correlation times. In order to differentiate sequence-neighbor effects from folding effects, two shorter peptides derived from P20, IATLK (P5) and NGRKIS (P6), were similarly 13C-enriched and investigated. For A43, T44, G48, and 151 residues in P20 relative to those in P5/P6, several observations are consistent with partial folding in P20: (1) C alpha H motional tendencies are all about the same, vary less with temperature, and are relatively more restricted, (2) G48 C alpha H2 phi (t) psi (t) rotations are more correlated, and (3) methyl group rotations are slower and yield lower activation energies consistent with formation of hydrophobic "pockets." In addition, T44 and 151 C beta H mobilities in P20 are more restricted at lower temperature than those of their C alpha H and display significantly greater sensitivity to temperature suggesting a larger enthalpic contribution to side-chain mobility. Moreover, at higher temperatures, side-chain methyls and methylenes in P20 are more motionally restricted than those in P5/P6, suggesting that some type of "folded" or "collapsed" structure remains in P20 for what normally would be considered an "unfolded" state.

Amino Acid Sequence↗
PubMed1997

In vitro incorporation of synthetic peptides into cells.

This article gives a specific example of how a reversible permeabilization kit can be adapted for use with a specific peptide-based protocol. It was relatively easy to design and run the control experiments to determine the necessary adaptations. The basic procedure given with the TRANS-PORT kit is amenable to modification such that is can be used with numerous other in vitro procedures.

Animals↗
PubMed1997

Construction of biologically active protein molecular architecture using self-assembling peptide-amphiphiles.

The peptide-amphiphiles described here provide a simple approach for building stable protein structural motifs using peptide head groups. One of the most intriguing features of this system is the possible formation of stable lipid films on solid substrates, or the use of the novel amphiphiles in bilayer membrane systems, where the lipid tail serves not only as a peptide structure-inducing agent but also as an anchor of the functional head group in the lipid assembly. The peptide-amphiphile system potentially offers great versatility with regard to head and tail group composition and overall geometries and macromolecular structures. For building materials with molecular and cellular recognition capacity, it is essential to have a wide repertoire of tools to produce characteristic supersecondary structures at surfaces and interfaces.

Drug Design↗
PubMed1997

Micropatterning gradients and controlling surface densities of photoactivatable biomolecules on self-assembled monolayers of oligo(ethylene glycol) alkanethiolates.

BACKGROUND: Bioactive molecules that are covalently immobilized in patterns on surfaces have previously been used to control or study cell behavior such as adhesion, spreading, movement or differentiation. Photoimmobilization techniques can be used, however, to control not only the spatial pattern of molecular immobilization, termed the micropattern, but also the surface density of the molecules--a characteristic that has not been previously exploited. RESULTS: Oligopeptides containing the bioactive Arg-Gly-Asp cell-adhesion sequence were immobilized upon self-assembled monolayers of an oligo(ethylene glycol) alkanethiolate in patterns that were visualized and quantified by autoradiography. The amount and pattern of immobilized peptide were controlled by manipulating the exposure of the sample to a UV lamp or a laser beam. Patterns of peptides, including a density gradient, were used to control the location and number of adherent cells and also the cell shape. CONCLUSIONS: A photoimmobilization technique for decorating surfaces with micropatterns that consist of variable densities of bioactive molecules is described. The efficacy of the patterns for controlling cell adhesion and shape has been demonstrated. This technique is useful for the study of cell behavior on micropatterns.

3T3 Cells↗
PubMed1996

Promotion of fibroblast adhesion by triple-helical peptide models of type I collagen-derived sequences.

The dissection of the activities mediated by type I collagen requires an approach by which the influence of triple-helical conformation can be evaluated. The alpha 1 beta 1 and alpha 2 beta 1 integrin binding sites within type I collagen are dependent upon triple-helical conformation and contained within residues 14-822 from alpha 1(I). Seven alpha 1(I)-derived triple-helical peptides (THPs) were synthesized based on charge clustering (alpha 1(I)256-270, alpha 1(I)385-396, alpha 1(I)406-417, alpha 1(I)415-423, alpha 1(I)448-456, alpha 1(I)496-507, and alpha 1(I)526-537). Three additional THPs were synthesized (alpha 1(I)85-96, alpha 1(I)433-441, and alpha 1(I)772-786) based on previously described or proposed activities (Kleinman, H. K., McGoodwin, E.B., Martin, G. R., Klebe, R. J., Fietzek, P. P., and Wooley, D. E. (1978) J. Biol. Chem. 253, 5642-5646; Staatz, W. D., Foik, K. F., Zutter, M. M., Adams, S. P., Rodriquez, B. A., and Santoro, S. A. (1991) J. Biol. Chem. 266, 7363-7367; San Antonio, J. D., Lander, A. D., Karnovsky, M. J., and Slayter, H. S. (1994) J. Cell Biol. 125, 1179-1188). Of the ten THPs, alpha 1(I)772-786 THP had the greatest activity, with half-maximal normal dermal fibroblast adhesion occurring at a peptide concentration of 1.6 microM. Triple-helicity was essential for activity of this sequence, as the non-triple-helical peptide analog (alpha 1(I)772-786 SSP) exhibited considerably lower levels of cell adhesion promotion even at peptide concentrations as high as 100 microM. Within the sequence itself, residues 784-786 (Gly-Leu-Hyp) were important for cellular recognition, as the alpha 1(I)772-783 THP had greatly reduced cell adhesion activity compared with alpha 1(I)772-786 THP. Preliminary studies indicate that the beta 1 integrin subunit mediates fibroblast adhesion to alpha 1(I)772-786 THP. The identification of fibroblast integrin binding sites within type I collagen may have important implications for understanding collagen metabolism.

Amino Acid Sequence↗