Self organizing bio structures
This presentation is the property of its rightful owner.
Sponsored Links
1 / 36

Self-Organizing Bio-structures PowerPoint PPT Presentation


  • 94 Views
  • Uploaded on
  • Presentation posted in: General

Self-Organizing Bio-structures. NB2-2008 L. Duroux. Lecture 7. Protein-based nanomaterials. 1. Peptide-based nanostructures. A first insight into SA peptides. Concept of peptide SA introduced by Ghadiri et al. (1993)

Download Presentation

Self-Organizing Bio-structures

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Self organizing bio structures

Self-Organizing Bio-structures

NB2-2008

L. Duroux


Lecture 7

Lecture 7

Protein-based nanomaterials


1 peptide based nanostructures

1. Peptide-based nanostructures


A first insight into sa peptides

A first insight into SA peptides

  • Concept of peptide SA introduced by Ghadiri et al. (1993)

  • Synthetic cyclic polypeptides (alternate L- & D-) self-assemble into Ø8-9nm nanotubes

  • Function as novel antimicrobial agents, drug delivery systems & nanomaterials


Ghadiri s cyclic polypeptides cpp

Ghadiri’s cyclic polypeptides (CPP)


Electronic microscopy

Electronic microscopy


Ph dependance of cp sa

pH-dependance of CP SA


Cpp forming pores in membranes

CPP forming pores in membranes


Self organizing bio structures

Self-Assembling Peptide Nanotubes

  • cyclic-peptides self-assembled into open tubes

  • consist of an even number of alternated D / L amino acids

  • formation of anti-parallel hydrogen bonded network

  • assembly could be controlled by electrostatic interactions

  • assembly could be directed toward particular environments (hydrophobic) by selection of amino acids

  • are functional material (ion channel & antibiotic)


Sa based on native 2 ndary structural motifs

SA based on native 2ndary structural motifs


Protein structural motifs sa designs

Protein structural motifs & SA designs

Amyloid fibrils

Type II polyPro helix


Sa fibers engineering based on coiled coils

SA Fibers engineering based on coiled-coils

Woolfson & Ryadnov, 2006


Amyloid peptides

Amyloid peptides

  • A generic, universal form of protein/peptide aggregation

  • Cause of many diseases: Altzheimer’s, Type II diabetes, Prions...

  • Extended b-sheet SA forming fibrils


Nano object formed by amyloid peptides

Nano-object formed by amyloid peptides

Object formed

Amyloid fibrils (pancreas type II diabetes)

Amyloid fibrils

Nanotubes

Nanospheres


The role of aromatics in amyloid fibrils formation

The role of aromatics in amyloid fibrils formation

  • Phe dipeptide: the recognition core of Altzheimer’s amyloid fibril

  • Forms nanotubes

  • Applications in nano-electronics


Sa based on amphiphilicity

SA based on amphiphilicity


Structures of peptides used in sa

Structures of peptides used in SA

Boloamphiphile

Amphiphile

Surfactant-like

Phenylalanine

dipeptide

Reches and Gazit, 2006


Peptide nanotubes

Peptide nanotubes

Applications

Nanotubes with Ca-binding and cell-adhesion  bone-like material

Idem, non-conjugated

Nanofibers forming hydrogel  matrix for tissue regeneration & engineering


Peptide amphiphile and tissue engineering

Peptide-Amphiphile and Tissue Engineering

SA fibers with CCCCGGGS(PO4)PGD: without Ca2+ (a) and Ca2+ (b)


Aromatic dipeptides

Aromatic dipeptides


Hydrophobic layers made with dipeptides

Hydrophobic layers made with dipeptides

Görbitz, 2006


Types of nanostructures from various dipeptides

Types of nanostructures from various dipeptides


Sa of val ala class

SA of Val-Ala class


Sa patterns of the phe phe class

SA patterns of the Phe-Phe class

Phe-Trp

Phe-Gly

Phe-Leu

Phe-Phe


Formation of nanotubes with phe phe dipeptides

Formation of nanotubes with Phe-Phe dipeptides


2 protein based sa nanotools

2. Protein-based SA nanotools


S layer proteins

S-layer proteins


What are s layer proteins

What are S-Layer proteins?

  • S stands for surface: glycoprotein subunits forming outer envelope of Bacteria and Archea

  • Periodic structures with defined physico-chemical properties (pore size)

  • Self_assemble into 2D layers to form monomolecular lattices: potential in nanobiotechnologies (scaffolds, patterning matrices)


Applications of s layers

Applications of S-layers

  • production of isoporous ultrafiltration membranes

  • supporting structures for defined immobilization or incorporation of functional molecules (e.g. antigens, antibodies, ligands, enzymes)

  • matrix for the development of biosensors including solid-phase immunoassays and label-free detection systems

  • Support and stabilizing matrices for functional lipid membranes, liposomes, and emulsomes

  • adjuvants for weakly immunogenic antigens and haptens

  • Matrix for controlled biomineralization and structure for formation of ordered arrays of metal clusters or nanoparticles (molecular electronics and nonlinear optics or catalysts)


S layer lattices

S-Layer lattices

100nm

Gram+ bacterium


Self assembled monomolecular layers

Self-Assembled monomolecular layers


S layer as template for psa detection

S-layer as template for PSA detection


Assembly of lipids on s layers

Assembly of lipids on S-layers

  • Non-covalent bonding

  • Electrostatic interactions between corrugated (inner) side of S-layer (carboxy groups) and charges on lipid head groups (zwitterions)

  • 2-3 contact points between protein and lipid: most lipids free to diffuse laterally: semi-rigid membrane


S layers as support for lipid membranes

S-layers as support for lipid membranes


Self assembly of a ion channel in s layers

Self-Assembly of a ion-channel in S-layers


Expected applications of s layer driven sa of lipid membranes

Expected applications of S-layer-driven SA of lipid membranes

  • Life Sciences:

    • Drug delivery

    • Diagnostics

    • Biosensors

  • Chemistry and material sciences

    • Bio-mineralization

    • Non-linear optics

    • Molecular electronics

    • Catalysis


  • Login