Peptides & Amino Acids

Clickable Arg9 peptide.

Penetratin is a cell-penetrating peptide (CPP), also known as a protein transduction domain (PTD), of which the first 16 amino acids are derived from the third helix of the Antennapedia protein homeodomain. Penetratin linked to a phosphodiester oligonucleotide is capable of permeating through neuronal cell membranes and down-regulating genes.

Myelin oligodendrocyte glycoprotein (MOG) is a type I integral membrane glycoprotein of the immunoglobulin superfamily (Ig) found exclusively in mammals. The 26-28 kDa protein is located on the external surface of the oligodendrocyte membrane, mostly on the peripheral lamellae of myelin sheaths of the Central nervous system (CNS). The immunodominant 35-55 epitope of MOG (MOG 35-55) is a primary target for both cellular and humoral immune responses1. Anti-MOG antibodies and the abnormal activation of encepalitogenic T cells upon recognition of MOG (35-55) peptide cause the destruction of myelin sheath during Multiple sclerosis (MS), a common inflammatory autoimmune disorder of the CNS. Although MOG is a minor component of the CNS, the 35-55 epitope of MOG (MOG 35-55) is strongly immunogenic and therefore is widely used for in vivo biological evaluation and immunological studies of the Experimental Autoimmune Encephalomyelitis (EAE), a mouse animal model for T-cell-mediated inflammatory

Apidaecin IB is a proline-rich antimicrobial peptide (PrAMP) isolated from Apis mellifera hemolymph. Apidaecin IB mainly possesses activity against Gram-negative bacteria. It has been reported that Apidaecin IB is a non-lytic AMP which enters the cell and inhibits an intracellular target, the chaperone DnaK. Apidaecin IB is not toxic for humans and animals. It has been studied for treating systemic bacterial infections.

Abaecin is a proline-rich cationic antimicrobial peptide (PrAMP) and was isolated from Apis mellifera. Abaecin is a 34 amino acid peptide including 10 prolines positioned uniformly which prevents the α-helical conformation.

Native Melan-A (26-35) decapeptide derives from the melanocyte lineage-specific protein Melan-A/MART-1, which is expressed in almost 75-100% of primary and metastatic melanomas. The region 26-35 of Melan-A protein acts as an antigenic peptide that is recognized by CD8+ tumor-reactive cytolytic T lymphocytes (CTLs) for designing antigen-specific cancer vaccines1. It has been shown that CD8+ Melan-A-specific CTLs isolated from melanoma patients efficiently lyse the Melan-A-expressing HLA-A*0201+ melanoma cell line. However, CTLs preferentially recognize the Melan-A (26-35) peptide as compared with the Melan-A (27-35) peptide. Moreover, the Melan-A (26-35) A27L analog (ELAGIGILTV) has a higher binding affinity to HLA-A*0201 than the native Melan-A (26-35) peptide (EAAGIGILTV), and consequently displays more potent antigenicity and immunogenicity. It has been reported that the concentration of Melan-A (26-35) A27L analog required to obtain 50% of maximal antigenic activity (EC50) is 0.01nM

MUC1 (Mucin 1) protein is a type 1 transmembrane glycoprotein characterized by a large extracellular domain containing a variable number (up to 120) of 20-amino acid repeat sequences (PDTRPAPGSTAPPAHGVTSA) and a high glycosylation level on serine and threonine residues within each tandem repeat. MUC1 protein is expressed at the apical part of secretory epithelial cells and is involved in the protection of epithelial surfaces as well as intracellular signalling. However, the aberrant MUC1 overexpression along with the modification of its glycosylation pattern has been associated with several carcinomas including more than 90% of breast and pancreas cancers as wells as hematologic malignancies such as multiple myelomas and lymphomas. These hallmarks make MUC1 highly immunogenic when its expressed in tumor cells and, thus, an attractive and broadly applicable target for cancer inmunotherapy. MUC1 has indeed prompted research to develop T-cell vaccine strategies capable of inducing MUC1-sp

Human Calcitonin (hCT) is a 32-amino acid hormone peptide belonging to the Calcitonin/Calcitonin-gene related peptide (CGRP) family, that also comprises amylin, adrenomedullin (AM) and adrenomedullin2/intermedin (AM2/IMD). Calcitonin is characterized by a N-terminal disulfide bond that forms a 7 amino acid ring structure, a region with a α-helix tendency and an amidated C-terminus1. Calcitonin peptide is produced by C cells of the thyroid gland and binds preferentially to the G-protein coupled receptor, calcitonin receptor (CTR)1. Calcitonin receptor signals through activated Gs protein and the production of cAMP second messenger molecules by adenylyl cyclase1. The dissociation constant (Kd) of calcitonin receptors expressed by a human ovarian small cell carcinoma line is approximately 4.6 nM for human Calcitonin2. Calcitonin is involved in the homeostasis of calcium and phosphorus, and the regulation of bone dynamics. At the basal state, calcitonin secretion reduces plasma calcium a

Exendin-4 is a 39-amino acid peptide incretin mimetic. Exendin-4, also known as Exenatide, was originally isolated from the venom of Gila monster lizard called Heloderma suspectum1. Exendin-4 is a long-acting analog of the mammalian intestinal hormone glucagon-like peptide I (GLP-1) and therefore exhibits glucoregulatory activities to control plasma glucose levels2. Exendin-4 enhances insulin synthesis and secretion in a glucose-dependent manner, while downregulating inappropriately high glucagon release, slowing gastric emptying and decreasing appetite2. The increase in maximum insulin secretion is due to a greater increase in cAMP production in pancreatic β cells3. Exendin-4 is a potent agonist of the Glucagon-Like Peptide-1 Receptor (GLP-1R ; Kd = 136pM). It has been reported that exendin-4 is a more potent insulinotropic agent when given intravenously to rats than is glucagon-like peptide-1 (GLP-1) as indicated by the lower ED50 (ED50 0.19 nmol/kg for glucagon-like peptide-1 versu