Peptide Lego and Self-Assembly Structure

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Questions and Answers

What characteristic of peptide Lego allows it to form well-ordered nanostructures?

They are only soluble in organic solvents.

They are hydrophilic in nature.

They use complementary ionic bonds for self-assembly. (correct)

They consist entirely of nonpolar amino acids.

What is the significance of the hydrophilic and hydrophobic surfaces in peptide Lego?

They prevent intermolecular self-assembly.

They facilitate intermolecular self-assembly in aqueous solution. (correct)

They promote van der Waals interactions exclusively.

They increase the temperature stability of the structure.

What type of structure do peptide Lego molecules typically form in aqueous solutions?

Well-formed nanofibers. (correct)

Spherical micelles.

Crystalline arrays.

Irregular aggregates.

Which of the following describes the peptide Lego discovered from Z-DNA binding protein?

It includes a segment found in yeast. Signup and view all the answers

What is a primary application of peptide scaffolds in biotechnology?

Creating 3-D cell culture environments. Signup and view all the answers

What role do functional motifs play in the context of self-assembled peptide structures?

They provide biocompatibility to the structures. Signup and view all the answers

Why do peptide Lego molecules utilize a beta-sheet structure during assembly?

It provides stability and orientation for further assembly. Signup and view all the answers

What is the average pore size in nanofiber scaffolds formed by peptide Lego?

5-200 nm. Signup and view all the answers

What is PuraMatrix primarily known for?

Its purity as a molecular designer biological scaffold Signup and view all the answers

What is the primary application of peptide scaffolds?

3-D cell culture Signup and view all the answers

Which of the following is true about the pore size of peptide scaffolds?

The pore size is 5-200 nm, suitable for biomolecular diffusion Signup and view all the answers

Which feature of peptide scaffolds contributes to their capability for slow drug release?

High water content and small pore size Signup and view all the answers

What is the difference between RADA16-I and traditional polymer scaffolds?

Traditional polymer scaffolds have a much larger fiber diameter Signup and view all the answers

What characterizes lipid-like self-assembling peptides?

They have hydrophobic tails and hydrophilic heads Signup and view all the answers

What effect do peptide scaffolds have on nutrient diffusion?

They enable slow diffusion of nutrients and growth factors Signup and view all the answers

What is the length and structure of the model peptides such as RAD16-I?

5 nm with an alternating arrangement of charged amino acids Signup and view all the answers

What happens to elastin-like proteins (ELPs) when apoCaM binds to Ca2+?

They assemble into meso–microscale particles. Signup and view all the answers

What role does EDTA play in the context of apoCaM and ELPs?

It chelates the bound Ca2+, reversing the transition. Signup and view all the answers

Which bacteria exhibited selective binding to Man-AuNPs?

The wild-type E. coli strain ORN178. Signup and view all the answers

What does the color change of lactose gold nanoparticles (AuNPs) indicate?

Aggregation and dispersion due to chemical interaction. Signup and view all the answers

What is suggested by the term 'glyconanoparticle'?

Nanoparticles that selectively bind to carbohydrates. Signup and view all the answers

What can be inferred about the mutant strain ORN208 in relation to Man-AuNPs?

It exhibits no binding activity. Signup and view all the answers

How does the RCA120 lectin influence lactose gold nanoparticles?

It induces aggregation followed by dispersion. Signup and view all the answers

What is a notable characteristic of the ELPs when combined with CaM?

Their assembly depends on Ca2+ binding. Signup and view all the answers

What is a key advantage of using protein nanopore sensors for DNA sequencing?

They allow label-free detection of ss-DNA. Signup and view all the answers

In the context of biomimetic assembly, what is the role of complementary proteins?

To facilitate the selective immobilization of nanowires. Signup and view all the answers

What external factors can trigger the changes in stimulus responsive nanomaterials?

pH, ionic strength, temperature, electric/magnetic fields, and photon. Signup and view all the answers

How do peptides act as actuators in stimulus responsive materials?

By altering spacing or volume through conformational changes. Signup and view all the answers

What type of geometry is achieved using biomimetic assembly with antibody nanotubes?

Cross-bar geometry. Signup and view all the answers

What is a primary characteristic of the nansensors developed from protein nanopores?

They detect current decay during ss-DNA translocation. Signup and view all the answers

What is the purpose of optimizing protein concentrations in the biomimetic assembly process?

To fabricate complex electric device geometries with high yields. Signup and view all the answers

What does the term 'peptide actuator' refer to in the context of responsive nanomaterials?

Peptides that induce swelling or shrinking in nanomaterial structures. Signup and view all the answers

What is the primary application of glyco-QDs in cell biology?

To analyze carbohydrate receptors Signup and view all the answers

Why do β-N-acetylglucosamine-encapsulated QDs concentrate at the sperm heads?

They interact specifically with GlcNAc receptors near the sperm heads Signup and view all the answers

What is the characteristic distribution pattern of mannose-encapsulated QDs on sperm?

Spread over the entire sperm body Signup and view all the answers

What technique is specifically mentioned for determining thermodynamic parameters of interactions in solution?

Isothermal titration calorimetry (ITC) Signup and view all the answers

In the context of glyconanoparticles, what is a key focus of the studies mentioned?

Studying carbohydrate-carbohydrate interactions Signup and view all the answers

What is the purpose of Lin’s technique mentioned in the content?

For capturing target proteins and mapping binding epitopes Signup and view all the answers

Which of the following QDs is associated with selective labeling on sea-urchin sperm heads?

β-N-acetylglucosamine-encapsulated QDs Signup and view all the answers

What does the term 'Glyco-QDs' refer to in the context provided?

Quantum dots associated with carbohydrate molecules Signup and view all the answers

Study Notes

Peptide Lego

Molecular-designed 'peptide Lego' can self-assemble into well-formed nanostructures
First peptide lego was discovered from a segment in a left-handed Z-DNA binding protein in yeast and called Zuotin
In aqueous solution, these peptides form beta-sheet structures with distinct hydrophilic and hydrophobic surfaces
The hydrophobic sides shield themselves from water, facilitating intermolecular self-assembly
These peptides form complementary ionic bonds with regular repeats on the hydrophilic surface

Self-assembly

Peptide of 16 amino acids, alternating polar/nonpolar, form stable β-strands and β-sheets
They create nanofibers through hydrophobicity, leading to matrices with high water content
By adjusting the peptide sequence, different fiber sizes and pore sizes can be achieved
Functional motifs can be integrated during the self-assembly process

Peptide Scaffolds - 3-D Cell Culture

Peptide Lego molecules self-assemble into well-ordered nanofibers and form scaffolds with nanopores ranging from 5-200 nm
RADA16-I, also known as PuraMatrix, is a widely used and commercialized peptide scaffold
These scaffolds resemble the structure of extracellular matrices and facilitate cell growth, migration, and nutrient diffusion
They are ideal for 3-D cell culture, controlled cell differentiation, regenerative medicine, and slow drug release applications

Lipid-like Self-assembling Peptides

These peptides have hydrophobic tails and hydrophilic heads, self-assembling in water
They have potential for use as protein nanopore sensors, enabling label-free sequence-specific DNA detection
This technology holds promise for developing economical DNA sequencing devices

Biomimetic Assembly - Multiple Nanowire

Biomimetic assembly allows for the selective immobilization of multiple nanowires with different antibodies on specific locations within electrical substrates
This method can fabricate complex electric device geometries with high yields
This technology has demonstrated the assembly of two antibody nanotubes into a cross-bar geometry using biomolecular recognition

Peptide and Protein Based Stimulus Responsive Materials

Stimulus responsive nanomaterials undergo changes with external stimuli like pH, ionic strength, temperature, fields, and photons
Peptides are used as actuators, altering the spacing or volume of nanomaterials through conformational changes
One example uses elastin-like protein (ELP) fused with calmodulin (CaM) to generate responsive actuators
Ca2+ binding causes ELP assembly into particles, while EDTA chelation reverses the process and produces monomers

Glyco-Nanotechnology

Glyconanoparticles use carbohydrate molecules to create functional nanomaterials
These particles have potential for use in drug delivery, diagnostics, and bioimaging
Glyconanoparticles can exhibit selective binding to specific cells or tissues based on their carbohydrate ligands

Applications of Glyconanoparticles

Mannose-AuNPs have demonstrated selective binding to the wild-type E.coli strain ORN178 but not to the mutant ORN208
This technology can be used to create reversible aggregation/dispersion behavior of nanoparticles through lectin and sugar interactions
Glyco-QDs can be utilized in cell biology research for analyzing carbohydrate receptors

Glyco-QDs

Glyco-QDs are applied in cell biology for analyzing carbohydrate receptors
They can be used for selective labeling of specific cells or tissues
For example, acetylglucosamine-encapsulated QDs concentrate on sperm heads, while mannose-encapsulated QDs distribute across the whole sperm body

Glyconanoparticles for studying carbohydrate–carbohydrate Interactions

Glyconanoparticles are used in isothermal titration calorimetry (ITC) to determine thermodynamic parameters of interactions in solution
This allows for studying the interactions between various carbohydrate molecules
This approach offers significant insight into the complex interactions within biological systems

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Description

Explore the fascinating world of peptide Lego and their ability to self-assemble into nanostructures. This quiz covers the molecular design, characteristics of β-strands and β-sheets, and the implications of peptide scaffolds in 3-D cell culture. Test your knowledge of these innovative materials and their applications in bioengineering.