Friday, March 16, 2012

As a way to introduce more customers to LifeTein antibody products, we are offering a limited time promotion on select epitope tag antibodies. $50 Anti-His monoclonal antibody. Please take a look at our product page for more details: http://ping.fm/WLW5U
Synthetic human potassium channel proteins Ether-a-go-go-related gene (HERG) peptides, synthesized by LifeTein, were used to study the protein structure and peptide binding activities. http://bit.ly/pAxoWm

Tuesday, March 6, 2012

Wang lab found that the apoE peptides potently inhibit HCV infection and suggest a direct role of apoE in mediating HCV entry. Peptides were synthesized by LifeTein. Their findings also highlight the potential of developing apoE mimetic peptides as novel HCV entry inhibitors by targeting HCV-host interactions. http://ping.fm/ZjT2o

Wednesday, February 29, 2012

Neiditch lab used synthetic peptide PhrF from LifeTein and found that the PhrF binding to RapF allosterically triggers its dissociation from ComA. http://ping.fm/WjOnD

Thursday, January 19, 2012

Cell-penetrating peptides (CPPs) cell entry mechanism updated: http://bit.ly/zwTQFx

Amino acid composition of cell-penetrating peptides

Cell-penetrating peptides (CPPs) such as the HIV TAT peptides are able to enter cell by direct translocation and endocytosis. HIV TAT or even simple poly-arginines can be effectively designed for drug delivery. However how cell-penetrating peptides, HIV TAT peptide for example, accomplish these cellular molecular transfer has so far been a mystery.

How does simple HIV TAT peptide facilitate mechanisms like direct translocation and multiple endocytotic processes? Researchers from Gerard Wong’s lab found how HIV TAT peptides can have multiple interactions with the cell membrane, the actin cytoskeleton and specific cell-surface receptors to produce multiple pathways of translocation under different conditions. Click here for the publication from Gerard Wong’s lab: http://bit.ly/zQrH6t.

Interestingly, TAT peptide can multiplex different interactions with the same sequence, thus interacting with the membrane, the actin cytoskeleton, and specific receptors to produce multiple pathways of translocation under different conditions.

CPPs entry mechanism is sensitive to the peptide sequence. The addition of a single hydrophobic residue to purely hydrophilic CPPs can drastically modify the translocation mechanism. For example, polyarginine (polyR), the simplest prototypical CPP, can induce the cell membrane pore formation. Hydrophobic amino acids create positive curvature by inserting into the membrane. Arginine simultaneously creates positive and negative curvatures, whereas lysine creates negative curvature along one direction only. This implies a compensatory relation between arginines and lysines/hydrophobes.

Why is the hydrophobic content of the TAT peptide relatively low if hydrophobicity can help generate negative Gaussian curvature? CPPs use less hydrophobic residues to generate saddle-splay curvature. This difference in sequences can potentially only induce transient pore-like translocation structures in the membrane and thus lead to shorter pore lifetimes for CPPs. Because of the amino acid composition for CPPs, the TAT peptide can mediate endocytosis with or without receptors.

Order your cell penetrating peptide now: http://ping.fm/pd9n4

The following table shows a selection of currently known CPPs, their origins and sequences.

http://bit.ly/zwTQFx

Tuesday, December 27, 2011

Sex peptide on female reproductive behaviour

Rafaeli lab used sex peptide, synthesized by LifeTein, to show that virgin females injected with Drosophila melanogaster SP (DrmSP), in addition to inhibition of pheromone production, also exhibited a suppression of calling behaviour and a significant reduction in the gene expression levels of the PBAN-receptor. http://bit.ly/pAxoWm