The anti-apoptotic factor Bcl-2 is over-expressed in B-cell lymphoma cells as their main survival mechanism by binding to IP3R2 on endoplasmic reticulum (ER). In this study, a cell-penetrating version of 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.
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 as internally quench or IQ peptides, they were used in fluorescence resonance energy transfer (FRET) assays to study the enzyme kinetics of Bar1.
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.
Peptides can be used in a wide variety of research applications:
81 oligopeptides were synthesized by LifeTein and tested for inhibition of Enterococcus faecalis V583. Three peptides were found to inhibit V583. One in particular (NH3-VAVLVLGA-COOH) possessed activity in picomolar concentrations, being >10^6 -fold more active than the only other two and showing inhibitory activity.
The fungal pathogen causes the skin disease for amphibians. Use of a potent antibiotic cocktail dramatically reduced culturable skin bacteria within 48 h. The synthetic peptides by LifeTein were used to reduce the skin bacteria.
SSkin bacteria provide early protection for newly metamorphosed southern leopard frogs (Rana sphenocephala) against the frog-killing fungus, Batrachochytrium dendrobatidis, Biological Conservation, 2015
Anti-inflammatory peptides were isolated from alcalase hydrolysates out of tuna cooking juice by-product. Synthetic peptides from LifeTein were used to confirm the inhibitory anti-inflammatory activity. The amino acid sequences of the two anti-inflammatory peptides isolated from AH hydrolysates were Pro-Arg-Arg-Thr-Arg-Met-Met-Asn-Gly-Gly-Arg (1543.8 Da) and Met-Gly-Pro-Ala-Met-Met-Arg-Thr-Met-Pro-Gly (1211.5 Da).
Peptide scanning involves the chemical synthesis of overlapping peptides covering the antigen sequence targeted by the investigated antibodies. Peptide truncations are used to further narrow down the epitope sequence and mutagenesis of each amino acid such as alanine substitution can also indicate the binding affinity. Cross-reactive epitopes were found in Borrelia burgdorferi p66.
Cell Penetrating Peptides and Scrambled Peptides
The CD81 peptides tagged with cell penetrating peptide RRRRRRR were used for binding assay. The synthetic peptides from LifeTein were used to investigate the role of CD81 in the regulation of defense mechanisms against microbial infections.
The scrambled peptides, RRRRRRR- CCGIRNSSVY, were used as the negative control for the study.
CD81 Controls Immunity to Listeria Infection through Rac-Dependent Inhibition of Proinflammatory Mediator Release and Activation of Cytotoxic T Cells, The Journal of Immunology, 2015
Receptor Binding Study
His-tagged GLP-1 (7-36), glucagon, and gastric inhibitory polypeptides (GIP) by LifeTein were used to study GLP-1 receptor signaling regulation. The GLP-1 peptides bind specifically with lipids but not that of exendin 4.The His-Tagged GLP-1 were used for the binding reaction. The free peptide were captured by Cu++-NTA resin. The results indicated that His-tagged GLP-1 peptide binds to OEA in a dose dependent and saturable way.
Antibody Blocking Peptides
Peptides can be used as blocking peptides for the competition assay. The excess of blocking peptides (20:1 peptide: antibody ratio) from LifeTein were mixed with antibodies. The antibody was neutralized in this way by incubating with an excess of peptide that corresponds to the epitope recognized by the antibody. The neutralized antibody is then used side-by-side with the antibody alone, and the results are compared.
The B-cell lymphoma 2 (Bcl-2) peptides were biotinylated at N terminus for the protein-protein interactions. The biotin-BH4-Bcl-XL peptide and the scrambled peptide were immobilized on different channels of a streptavidin-coated sensor chip. Studies showed that Bcl-XL bound to the central domain of RyR3 via its BH4 domain. Further analysis of a mutated peptide at a specific site Lys87 showed a reduced binding affinity. These data suggest that BH4 domain and its specific site of Lys87 contributes to the interaction.
Check the cancer peptide database for a list of tumor peptides.
Tumor antigens can be classified into two categories based on their pattern of expression: tumor-specific antigens (TSA) and tumor-associated antigens (TAA).
LifeTein can customize a discovery and development path to fit your exact needs for peptide synthesis.