Endothelin 1, human, FAM-labeled

Product Name: Endothelin 1, human, FAM-labeled

Sequence One Letter Code: FAM-CSCSSLMDKECVYFCHLDIIW (Disulfide bridge: 1-15 and 3-11)

Sequence Three Letter Code: FAM-Cys-Ser-Cys-Ser-Ser-Leu-Met-Asp-Lys-Glu-Cys-Val-Tyr-Phe-Cys-His-Leu-Asp-Ile-Ile-Trp-OH (Disulfide bridge: 1-15 and 3-11)

Chemical Formula:C130H169N25O38S5

Molecular Weight: 2850.3

Purity: 95%

Form: Lyophilized

Storage Conditions: - 20 °C Protected from light

Research Area: Peptide Series

Source / Species: human

Conjugation: Conjugated

Conjugation Type: Fluorescent dyes

Code Nacres: NA.26

Application: Endothelin-1, human, FAM-labeled, is a fluorescently tagged derivative of the potent vasoactive peptide endothelin-1, developed for receptor binding and signaling studies. Endothelin-1 is produced primarily by endothelial cells and regulates vascular tone through activation of endothelin receptors, members of the G protein–coupled receptor family. Receptor stimulation triggers intracellular signaling cascades, including phospholipase C activation and protein kinase C (PKC) signaling. Dysregulated endothelin-1 activity has been implicated in hypertension, cardiovascular dysfunction, and early diabetic vascular complications. Conjugation of 5-carboxyfluorescein (FAM) at the N-terminus enables direct fluorescence-based detection, with excitation and emission maxima at 494 and 521 nm, respectively. This labeling supports visualization of ligand–receptor interactions, receptor internalization, and downstream signaling dynamics in cellular systems. The peptide is well suited for mechanistic studies of endothelin receptor pharmacology and vascular disease–related signaling pathways.

Current Research: Endothelin-1, human, FAM-labeled, is a fluorescent derivative of the 21-amino acid vasoactive peptide endothelin-1 (ET-1), developed to support receptor binding, trafficking, and signal transduction studies. Native endothelin-1 is produced primarily by vascular endothelial cells and is one of the most potent endogenous vasoconstrictors identified. Through activation of endothelin receptors ETA and ETB—both members of the G protein–coupled receptor (GPCR) superfamily—ET-1 regulates vascular tone, smooth muscle contraction, and multiple downstream cellular responses. Binding of endothelin-1 to its receptors initiates G protein–mediated signaling cascades, prominently involving phospholipase C (PLC) activation. PLC-mediated hydrolysis of phosphatidylinositol 4,5-bisphosphate generates inositol trisphosphate (IP₃) and diacylglycerol (DAG), leading to intracellular calcium mobilization and activation of protein kinase C (PKC). These signaling events contribute to sustained vasoconstriction, modulation of gene expression, and regulation of cell proliferation and fibrosis. Dysregulated endothelin signaling has been implicated in hypertension, pulmonary arterial hypertension, cardiac hypertrophy, chronic kidney disease, and early vascular complications associated with diabetes. Conjugation of 5-carboxyfluorescein (FAM) at the N-terminus enables direct fluorescence-based detection of the peptide without requiring secondary labeling reagents. FAM exhibits excitation and emission maxima at approximately 494 nm and 521 nm, respectively, making the probe compatible with standard FITC filter sets in fluorescence microscopy, flow cytometry, and plate-based assays. The fluorescent tag allows real-time visualization of ligand–receptor interactions in both live-cell and fixed-cell systems. Endothelin-1, human, FAM-labeled, supports detailed investigation of receptor binding kinetics and spatial distribution. Fluorescence-based binding assays can be used to quantify receptor occupancy, determine apparent affinity, and perform competitive displacement studies with unlabeled agonists or antagonists. In imaging applications, the probe enables visualization of receptor localization at the plasma membrane and subsequent internalization following ligand stimulation. These studies are particularly valuable for analyzing receptor trafficking dynamics, including endocytosis, recycling, or degradation pathways. The fluorescent peptide also facilitates integration of binding and signaling analyses. By combining imaging with calcium flux measurements or PKC activation assays, researchers can correlate receptor engagement with downstream functional responses. This approach supports mechanistic exploration of receptor subtype–specific signaling, biased agonism, and differential pathway activation in vascular smooth muscle cells, endothelial cells, and receptor-expressing model systems. In cardiovascular research, the probe provides a tool for studying endothelin receptor expression patterns and altered signaling under pathological conditions. For example, enhanced ETA receptor activity is associated with vasoconstrictive and proliferative effects, while ETB receptor signaling can mediate both vasodilation and clearance of circulating endothelin-1. Fluorescently labeled endothelin-1 allows experimental differentiation of receptor behavior and evaluation of selective antagonists used in therapeutic development. Overall, Endothelin-1, human, FAM-labeled, offers a sensitive and versatile platform for analyzing endothelin receptor pharmacology. Its defined biological activity combined with fluorescence-based traceability enables detailed examination of ligand binding, receptor internalization, and intracellular signaling pathways. This makes it a valuable reagent for mechanistic studies of vascular regulation and disease-associated endothelin signaling dysfunction.