Product Spotlight for 11/19/19: Stock Market Listings

In conjunction with our bulk stock sale and the deep discounts offered, here is an overview of some of the choice items available, along with some properties that make them so relevant to their particular areas of research.

Biologically Active Peptides
Cell Penetrating Peptides
(CPPs), or protein transduction domains (PTD), are peptides, usually with fewer than 30 residues, that have emerged in recent years as an effective means to transport therapeutic compounds into cells. They have the ability to cross cell membranes and can be conjugated with cargo molecules, which can enter into a cell with the cargo remaining intact.1-4

Ac-cyclo [Pen-Tyr(Me)-Ala-Arg-Gly-Asp-Asn-Tic-Cys]-NH2

Another cyclized RGD peptide, Cilengitide (Cyclo(Arg-Gly-Asp-D-Phe-N-Me-Val)), is a selective inhibitor of αvβ3 and αvβ5 with a possible role in tumor therapy.5-9


Peptides International has industry-leading catalog offerings and expertise with RGD and cyclized peptides available for your research.

Fibronectin Adhesion-Promoting Peptide

Proteinase-Activated Receptor (PAR) is a unique member of the G protein-coupled receptor (GPCR) family that is activated primarily by proteases. Protease cleavage exposes a tethered ligand at the N-terminus that binds to a conserved region in the second extracellular loop, leading to intracellular signaling. Recent findings suggest a complete shift in thinking regarding the roles of proteases as signaling molecules that can act as agonists or antagonists.11

PAR1 and PAR2 are expressed by a wide number of tumor cells including breast and colon cancers, suggesting a role in angiogenesis.10,12 For these and other diseases where PAR plays a central role, the receptor may act as a potential therapeutic target.



Peptides International offers a variety of PAR-AP agonists and antagonists for your research needs.

Enzyme Inhibitors and Substrates
The classic protease inhibitor Leupeptin is one of our most popular products and been featured many times in our pages as well. It has been implicated in the inhibition of many processes, including tumorigenesis13, protection of cochlear and vestibular hair cells from gentamicin (GM) ototoxicity14, myocardial stunning15, among many others.


Another very popular item is Chymostatin. A group’s results in a recent publication showed that the inflammatory process can be influenced by impeding the arrival of polymorphonuclear cell (PMN) recruitment into the surgically injured site using the mMCP-4 inhibitor.16


E-64 is an inhibitor for thiol proteases and a calpain inhibitor, been broadly used as a diagnostic inhibitor of cysteine proteases in vitro, and has, in some studies, extended its application to living tissues.17


Ac-Phe-Thiaphe-OH, also known as N-Acetyl-L-Phenylalanyl-L-3-Thiaphenylalanine, is a dipeptide mimetic substrate for CarboxypeptidaseA. A colorimetric assay that utilizes Ellman's reagent to detect the thiophenol released upon cleavage of the peptide, has been developed. In turn, the assay can then be used for the direct determination of carboxypeptidase A in serum.18


Tools for Peptide Synthesis
Our final entry is a xylosylated L-serine, and is a useful building block for the synthesis of glycopeptides.19


All of these items, and hundreds more, are currently available for some of the deepest bulk discounts that we have ever offered! Simply click on the link at the bottom of any respective product’s webpage similar to the image seen below or contact us via email.


  1. K. Toyama, et al., Bioconjugate Chem., 29, 2050 (2018).
  2. H. Räägel and M. Pooga, Peptide and Protein Delivery, 2011.
  4. Molecules 2015, 20, 13055-13070; doi:10.3390/molecules200713055
  5. L. Zhang, et al, Clin Transl Oncol. (2019).
  6. H. Faun, et al, Nat Commun, 9(1), 3524 (2018).
  7. S. Yamada, et al, Neurosurgery, 59(6), 1304 (2006).
  8. N.C.Cheng, et al., PLoS One, 9, e90374 (2014).
  9. C.Mas-Moruno, et al., Anticancer Agents Med. Chem., 10, 53 (2010).
  10. M.D. Hollenberg and S.J. Compton, Pharm. Rev., 54, 203 (2002). (Review)
  11. D. Darmoul, et al., Am. J. Patho., 162, 1503 (2003).
  12. Even-Ram, et al., Nat. Med., 4, 909 (1998).
  16. J. Succar, et al., Advances in Wound Care, 8, 10 (2019).
  17. C.A. Carrión, et al., J Exp Bot., 64(16), 4967 (2013). doi: 10.1093/jxb/ert285
  18. K.S. Brown, W.D. Kingsbury, N.M. Hall, G.L. Dunn, and C. Gilvarg, Anal. Biochem., 161, 219 (1987).
  19. N. Yao, et al., Carboh. Res., 340(15), 2277 (2010).