S-layer proteins

messengerrushΒιοτεχνολογία

22 Φεβ 2013 (πριν από 4 χρόνια και 3 μήνες)

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S
-
layer proteins

Potential Application in
Nanobiotechnology

The beginning of Biotechnology

S
-
layer Proteins



Challenges of Biotechnology:


Nano structured surfaces


Self assembled structures in the few to tens of
nanometers


Problematic to graft with Lithographic techniques


Too big for classical chemical synthesis


Microorganisms to synthesis structures

S
-
layer Proteins


Aim of Applied Molecular engineering



Design of self assembling nanostructures



DNA


Proteins


Lipids


DNA self assembly

DNA Origami

DNA Origami

S
-
layer Proteins


DNA based functional Nanostructures:



2D lattices


3D cages


Networks of DNA structures interfaced with
proteins, e.g. Streptavidin

S
-
layer Proteins


Protein based functional nanostructures:


proteins as patterning elements


Self assembling fusion proteins to form 2D and 3D
structures


As an alternative to engineered and designed
fusion proteins that self assemble into larger
patterns is to exploit naturally self assembling
proteins into crystalline patterns


S
-
layer Proteins


The cell surface envelope proteins (S
-
layer
proteins) (Sleytr et al., 1999)


S
-
layer proteins are the outermost component
of the cell envelope


They represent a universal feature of archea.


E.g. Haloferax Volcanii has its surface covered
to 98 % with S
-
layer proteins


Gram positive bacteria such as Micrococcus
lysodeicticus contains S
-
layer proteins

S
-
layer Proteins


S
-
layer lattices are composed in most cases of
a single protein or glycoprotein species,

that self assemble into


Oblique


Hexagonal


Square


symmetry


S
-
layer proteins


S
-
layer Proteins

S
-
layer Proteins

Electron Micrograph of a
gram positive bacterium
with a square p4 S
-
layer
lattice

S
-
layer Proteins

S
-
layer proteins

S
-
layer Proteins


S
-
layer proteins are a first order self assembly
system that has been optimised during the
course of evolution.


In bacteria the S
-
layer proteins are linked to
each other and the underlying cell envelope
by


Non covalent forces


These proteins can maintain their self
assembly potential even after isolation.

S
-
layer Proteins


S
-
layer Proteins

S
-
layer Proteins

S
-
layer Proteins


S
-
layer Proteins


The s
-
layer cyrstal lattices as found on the
outside of bacterial cells can be restored on


Synthetic substrates such as.


Silicon wafers


Noble metal surfaces


Langmuir lipid films


Liposomes


plastics

S
-
layer proteins

S
-
layer assembly in Solution

Crystal growth at interfaces

S
-
layer growth on Si surfaces

S
-
layer Proteins

Patterning of S
-
layers on Si surfaces

S
-
layer Proteins


S
-
layer Proteins patterning by soft
lithography


S
-
layer Proteins

S
-
layer Proteins

S
-
layer Proteins

S
-
layer Proteins

S
-
layer Proteins

S
-
layer Proteins

S
-
layer Proteins

S
-
layer Proteins

S
-
layer Proteins

S
-
layer Proteins

S
-
layer Proteins

S
-
layer Proteins Biomimetic cell
membranes

S
-
layer Proteins: Biomimetic lipid
membrane

S
-
layer supported lipid membranes

S
-
layer Proteins

S
-
layer Proteins