Category Archives: Peptide

Peptide synthesis services, custom peptide synthesis services

How HIV-1 integrase contributes to virion morphogenesis?

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It was found that the HIV-1 Integrase binds the Viral RNA genome and is essential during Virion Morphogenesis. The L50 Peptide: Cyclo-(-Arg-Val-Arg-Thr-Arg-Gly-LysArg-Arg-Ile-Arg-Arg-DPro-Pro-) was synthesized by LifeTein and used for the inhibition assays. The L50 is a Tat-derived peptide sequence, which selectively engages both the loop and 3-nt bulge
but not the double-stranded stem of the transactivation response. The TAT-derived peptide is a well-defined cell penetration peptide.

HIV-1 Integrase Binds the Viral RNA genome

Cell Penetration Peptides

Cell Penetration Peptides

Monitoring T cell–dendritic cell interactions in vivo using labeled peptides

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The SrtA substrates Biotin–aminohexanoic acid–LPETGS and SELPETGG were used to interact with immune cells ‘Labelling Immune Partnerships by SorTagging Intercellular Contacts’ (LIPSTIC). The peptide-receptor interactions enable the direct measurement of dynamic cell-cell interactions. The peptides are flexible tools with different receptor-ligand pairs and a range of detectable labels.

peptide-receptor interaction

Schematic representation of the LIPSTIC approach

 

Nature, Monitoring T cell–dendritic cell interactions in vivo by intercellular enzymatic labeling

Peptide Biotin–aminohexanoic acid–LPETGS, SELPETGG was purchased from LifeTein.

How do peptides fold?

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peptide fold

Short Peptide Folding

How does the amino acid sequence of a protein chain determine and maintain its 3D folded state? How do small proteins fold?

Short Peptide Folding

Many small proteins or miniproteins are peptides shorter than 40-50 residues with stable folding that contain secondary structure elements such as alpha helices and beta strands.

An autonomously folding, 35-residue, thermostable subdomain (HP36) of the villain headpiece is the smallest folded domain of a naturally occurring protein. Polypeptides simplify the protein-folding problem. They allow in-depth examinations of sequence-structure-stability relationships without using the complex larger proteins.

In this recent study, Rocklin et al. designed sequences intended to fold into desired structures. The novel proteins may be helpful in bioengineering or pharmacological applications.

Check the paper from here: https://goo.gl/Tregb7

http://science.sciencemag.org/content/357/6347/168

LifeTein Launches Rush Custom Peptide Synthesis Service: Peptide Delivered in 3-5 Days

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Peptide-Library
Peptide-Library

LifeTein is unveiling an expedited peptide synthesis program, promising to place peptides in its customers’ hands within 3-5 business days. The RushPep™ peptide synthesis service was designed to circumvent the existing limitations of conventional solid-phase peptide synthesis (SPPS), which involves a long coupling time and low yield. RushPep™ shortens the time needed for individual coupling, deprotection, and washing steps. The proprietary methodology renders processing ten times faster than in classical synthesis while circumventing the limitations caused by forming by-products or intermediates to which traditional SPPS approaches are subject.

LifeTein’s Rush Custom Peptide Synthesis Service

“When designing the RushPep™ methodology, our focus was not only to produce peptides of high quality and purity but also to offer a streamlined solution that would increase the efficiency of researchers’ protein discovery workflows,” stated Dr. Ya Chen, Head of LifeTein’s Rush Peptide Synthesis Group. “RushPep™ achieves these goals by synthesizing the peptides in 3–5 business days to accelerate research and discovery.”

Chen continued, “The reliability of RushPep™ rush peptide synthesis ensures that the peptides are finished in 3–5 business days with high-batch-to-batch reproducibility. ” Most of the crude peptides have a purity of over 80%. RushPep™ peptide service is valuable for scientists and researchers because it allows them to finish their proteomics projects quickly and cost-effectively.

ID2 peptide for inhibition of tumour growth

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Biotinylated wild-type and modified (pT27 and T27W) ID2 peptides (amino acids 14–34) were synthesized by LifeTein. ID2 binds to the VHL ubiquitin ligase complex. This ID2 peptide could be used to inhibit tumor growth in patients with glioblastoma.

LifeTein’s ID2 Peptides Can Inhibit Tumour Growth

Nature, 529, 172–177 (14 January 2016) doi:10.1038/nature16475, An ID2-dependent mechanism for VHL inactivation in cancer.

How BIRD-2 Peptide Takes Down B-Cell Lymphoma?

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The anti-apoptotic factor Bcl-2 is over-expressed in B-cell lymphoma cells as their primary survival mechanism by binding to IP3R2 on the endoplasmic reticulum (ER).  In this study, a cell-penetrating version of the BIRD-2 peptide (Bcl-2/IP3R Disrupter-2 peptide with a TAT sequence) made by LifeTein was used to break up the complex formed by Bcl-2 and IP3R2 in human diffuse large B-cell lymphoma (DLBCL) cells. Ca2+ signaling-related events are suggested to be the killing mechanism of BIRD-2 peptide on DLBCL cells.

BIRD-2, a peptide that explicitly disrupts the Bcl2/IP3R complex, was utilized to further verify the mitochondrial Ca2+ regulatory mechanism via the Bmal1-Bcl2/IP3R signaling pathway. It was found that BIRD-2 aggravated mitochondrial Ca2+ overload and apoptosis in vitro.

Purchase BIRD-2 peptide now. Click here.

BIRD-2 peptide (sequence: RKKRRQRRRGGNVYTEIKCNSLLPLAAIVRV) was purchased from LifeTein (South Plainfield, NJ, USA) with a purity of >85%.

Bird-2 Peptides & B-Cell Lymphoma

Reference:

BIRD-2 peptide (LifeTein, USA), specifically disrupting the Bcl2/IP3R complex, was used in HGHP-treated H9c2 cells for 12 h (20 μM)

Inhibiting Bcl-2 via its BH4 domain in DLBCL cancers to provoke pro-apoptotic Ca2+ signaling

BIRD-2, a BH4-domain-targeting peptide of Bcl-2, provokes Bax/Bak-independent cell death in B-cell cancers through mitochondrial Ca2+-dependent mPTP opening

Look Who’s Talking

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Intraspecies pheromone signaling regulated by proteases is critical for fungi procreation.  The fungal aspartyl protease Bar1 was shown to have unique substrate specificity of important implications in fungal evolution.  LifeTein synthesized substrate peptides of Bar1, dual-tagged with DABCYL and EDANS, from the sequence of α pheromone, the native target of Bar1. Referred to as internally quenched or IQ peptides, they were used in fluorescence resonance energy transfer (FRET) assays to study the enzyme kinetics of Bar1.

LifeTein’s Internally Quenched Peptides

mBio 6(6):e01604-15. doi:10.1128/mBio.01604-15. Evolutionary selection on barrier activity: Bar1 is an aspartyl protease with novel substrate specificity.

A New Patent Using Peptides

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A patent has been published that describes new methods of manipulating plant stomatal development by artificially controlling how CRSP is expressed in plant cells.  The cleavage of epidermal patterning factor 2 (EPF2) by a serine protease CRSP is a key regulating mechanism in plant stomatal development.  A 30-mer EPF2 peptide, dual-tagged with DABCYL and EDANS, was synthesized by LifeTein to evaluate the protease activity of synthetic CRSP in a FRET assay.

New Patent Using Peptides Synthesized By LifeTein

Compositions and methods for mediating plant stomatal development in response to carbon dioxide and applications for engineering drought tolerance in plants.

Nanoparticles Get Help from Cell-Permeable Peptides

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Some cell-permeable peptides can carry cargo across the cell membrane even without any covalent links. Biotinylated peptides, including L—and D-TAT peptides made by LifeTein, were used in this study to show that two types of cell surface receptors, heparan sulfate proteoglycans, and Neuropilin-1, play critical roles in the delivery of silver-based nanoparticles into cells by cell-permeable peptides.

Nano Particles & Cell-Permeable Peptides

Science Advances 06 Nov 2015: Vol. 1, no. 10, e1500821 DOI: 10.1126/sciadv.1500821.  Neuropilin-1 and heparan sulfate proteoglycans cooperate in cellular uptake of nanoparticles functionalized by cationic CPP peptides.