Exploring the Role of Methylated Peptides in Histone Methylation: A LifeTein Perspective

Posted on February 21, 2018 by LifeTein Peptide

Post-translational modifications (PTMs) of histone proteins, such as acetylation, methylation, and phosphorylation, are pivotal in regulating chromatin dynamics. Among these, the role of methylation, particularly at arginine or lysine residues, stands out for its complexity and significance. LifeTein, a leader in peptide synthesis, has contributed significantly to this field by synthesizing mono-, di-, or tri-methylated peptides. These peptides are instrumental in studying protein-protein interactions, especially in the context of histone methylation.

Histone methylation, a process that can signal either transcriptional repression or activation, is increasingly recognized for its interrelation with DNA methylation in mammals. For instance, the targeting of DNA methylation is intricately linked to H3K9 methylation, a key regulatory mechanism in gene expression. The p53 gene, known as the guardian of the genome and frequently mutated in human cancers, is regulated by various PTMs, including methylation.

LifeTein’s contribution to this research is highlighted in a study focusing on the ASHH2 CW domain, which is responsible for recognizing the methylation state at lysine 4 of histone 3 N-terminal tails. This domain is crucial in recruiting the ASHH2 methyltransferase enzyme to histones. The study utilized H3 histone tail mimicking peptides, specifically monomethylated (ARTK(me1)QTAR), dimethylated (ARTK(me2)QTAR), and trimethylated (ARTK(me3)QTAR) peptides, all synthesized by LifeTein with a remarkable 95% purity as confirmed by mass spectrometry.

The research documented the assignment of a shortened ASHH2 CW construct, CW42, which showed similar binding affinity and better expression yields than previous constructs. This advancement is significant in understanding how different methylation states affect protein-peptide interactions. The study also performed 1H–15N HSQC-monitored titrations to determine the saturation point of the protein-peptide complex. The findings revealed that the CW42 domain, when bound to the monomethylated histone tail mimic, showed similar perturbations in shifts as the di- and tri-methylated instances.

In summary, LifeTein’s synthetic methylated peptides have been instrumental in advancing our understanding of histone methylation. Their high-purity peptides have enabled researchers to delve deeper into the complexities of chromatin dynamics and gene regulation, paving the way for future discoveries in epigenetic therapies and cancer treatment.

Read the full article on SpringerLink](https://link.springer.com/article/10.1007/s12104-018-9811-x) for more detailed insights into this groundbreaking research.

Noble metal gold and silver nanoparticle are conjugated with peptides for cellular imaging

Posted on February 15, 2018 by LifeTein Peptide

Noble metal gold (Au) and silver (Ag) nanoparticle (NPs) are used to conjugate with M3 peptides. The AuNPs-sGFP andAuNPs-M3 peptide form SERS active hot spot through self-assembly and GFP complementation. The nanoparticles self-assemble into surface-enhanced Raman-scattering (SERS) nanoclusters. The nanocluster can be used as contrast agents for multimodal SERS and photoacoustic microscopy with single-cell sensitivity.

AuNPs coated with M3 peptides-GFP

Reference: M3 peptide was purchased from LifeTein.

Cellular imaging by targeted assembly of hot-spot SERS and photoacoustic nanoprobes using split-fluorescent protein scaffolds

https://www.nature.com/articles/s41467-018-03046-w

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Custom Chemical Synthesis Other Posts: How to generate highly stable D-amino acid analogs of bioactive helical peptides? A six-mer synthetic peptide (AT1002) showed enhanced nasal drug delivery A simple protocol: Maleimide labeling of peptide and other thiolated biomolecules

How to generate highly stable D-amino acid analogs of bioactive helical peptides?

Posted on February 12, 2018 by LifeTein Peptide

Using D-amino acids as the building blocks for bioactive peptides can dramatically increase their potency. In this study, the authors generated a database of ∼2.8 million D-peptides using a mirror image of every structure in the Protein Data Bank (PDB). The critical or hotspot residues were studied. Residues critical to target binding and activity can then be ideally done experimentally such as alanine scanning mutagenesis. It can also be carried out computationally such as thermodynamic integration or free energy perturbation.

D-Amino Acids for Bioactive Peptides

Two peptides were tested to prove the concept: GLP-1 and Parathyroid Hormone. Both (L)- and (D)-peptides were synthesized by Lifetein LLC.

GLP-1 is a helical GPCR agonist as a diabetes mellitus and obesity treatment. Hotspot and junction residues are annotated in green and blue, respectively. The authors investigated the ability of (D)-GLP1 peptide to induce activation of GLP1R and compared the response with native (L)-GLP1 peptide. It was found that the D-GLP-1 performed well and resistance to protease degradation. The retro-inversion (RI) reversing the (D)-peptide sequence was used in the experiment.

D amino acid peptides

Glucagon-Like Peptide 1, GLP – 1 (7 – 36), amide, human:
HAEGTFTSDVSSYLEGQAAKEFIAWLVKGR – NH2

2. Parathyroid Hormone (PTH) is an FDA-approved treatment for osteoporosis. The (D)-PTH activates PTH1R with a potency and efficacy comparable to (L)-PTH. And more than 85% of the (D)-PTH analog is still detectable at six hours.

PTH 1-34: SVSEIQLMHNLGKHLNSMERVEWLRKKLQDVHNF

Conclusion: The D-Protein Data Bank (PDB) can be used to search and find therapeutically active topologies. The D-PDB could be a key tool for finding stable lead molecules in early-stage drug discovery.

Hot spot residues for receptor binding

Reference:

Method to generate highly stable D-amino acid analogs of bioactive helical peptides using a mirror image of the entire PDB

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Noble metal gold and silver nanoparticle are conjugated with peptides for cellular imaging

A six-mer synthetic peptide (AT1002) showed enhanced nasal drug delivery

A simple protocol: Maleimide labeling of peptide and other thiolated biomolecules

A six-mer synthetic peptide (AT1002) showed enhanced nasal drug delivery

Posted on February 12, 2018 by LifeTein Peptide

Zonula occludens toxin (Zot) and its biologically active fragment, delta G, have been shown to reversibly open tight junctions (TJ) in endothelial and epithelial cells. AT1002, a six-mer synthetic peptide H-FCIGRL-OH of ZO toxin was identified and synthesized that retains the Zot permeating effect on intercellular TJ. It was found that AT1002 disrupts the epithelial barrier while larazotide acetate restores barrier function by rearrangement of actin. In addition, AT1002 enhances the transport of molecular weight markers or agents with low bioavailability with no cytotoxicity. So this synthetic peptide AT1002 is a tight junction modulator with promising permeation-enhancing activity.

A Synthetic Peptide Showed Enhanced Nasal Drug Delivery

The C-terminal amidated AT1002 FCIGRL-NH2 showed enhanced nasal drug delivery and may lead to the development of a practical drug delivery technology for drugs with low bioavailability. The synthetic peptide AT1002 was synthesized by LifeTein.

Peptide amidation

https://bmcbiol.biomedcentral.com/articles/10.1186/s12915-018-0481-z https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4383222/

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New Service Available now: Order Gene Synthesis Service!

Posted on February 8, 2018 by LifeTein Peptide

Order your Gene Synthesis Service at a competitive price! Now it is 30% off. Email us at gene@lifetein.com for a quote.

LifeTein Gene Synthesis Service

Order now: https://www.lifetein.com/protein-expression-service.html

Oligo-peptide conjugation

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How do peptides fold?

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

How HIV-1 integrase contributes to virion morphogenesis?

Posted on January 30, 2018 by LifeTein Peptide

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 transactivation response. The TAT-derived peptide is a well-defined cell penetration peptide.

HIV-1 Integrase Binds the Viral RNA genome

Cell Penetration Peptides

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

Posted on January 30, 2018 by LifeTein Peptide

The SrtA substrates Biotin–aminohexanoic acid–LPETGS and SELPETGG were used for the interactions between 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 for use with different receptor–ligand pairs and a range of detectable labels.

Schematic representation of the LIPSTIC approach

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

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

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How do peptides fold?

How HIV-1 integrase contributes to virion morphogenesis?

How do peptides fold?

Posted on September 15, 2017 by LifeTein Peptide

Short Peptide Folding

How does the amino acid sequence of a protein chain determine and remain 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 villin headpiece, is the smallest folded domain of a naturally occurring protein. So, polypeptides simplify the protein-folding problem. It allows 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 useful in bioengineering or pharmacological applications. Check the paper from here: https://goo.gl/Tregb7 http://science.sciencemag.org/content/357/6347/168

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

Posted on March 29, 2016 by LifeTein Peptide

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 simultaneously circumventing the limitations caused by the formation of 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 to 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 the scientists and researchers because it allows them to finish their proteomics projects in a fast and cost-efficient manner.

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Peptides for Parkinson’s disease (PD)

ID2 peptide for inhibition of tumour growth

How does BIRD-2 peptide kill B-cell lymphoma?

Look Who’s Talking

Peptides for Parkinson’s disease (PD)

Posted on January 14, 2016 by LifeTein Peptide

All peptides used in this study for Parkinson’s disease were synthesized by LifeTein. The α-synuclein is an indication in the pathogenesis of Parkinson’s disease. It was found that a molecular mimicry mechanism between HSV1 and human α-synuclein could trigger PD.