pGluHisProNH2

pGluHisProNH2 is a short synthetic peptide composed of three amino-acid residues: pyrolidone form of glutamate (pyroglutamate) at the N-terminus, followed by histidine, and a C-terminal amide capping its proline residue. In this nomenclature, pGlu denotes the N-terminal pyroglutamyl modification, and NH2 indicates that the C-terminus is amidated. The result is a tripeptide with a blocked N-terminus and a neutral or near-neutral overall charge depending on pH.

The molecule is commonly described as pyroglutamyl-histidyl-proline amide, abbreviated as pGlu-His-Pro-NH2. The presence of the pyroglutamate residue can enhance metabolic stability by reducing aminopeptidase susceptibility, while the proline residue introduces conformational rigidity that can influence peptide geometry and interactions. Histidine provides a potential site for protonation under physiological conditions, which can affect binding characteristics and solubility.

Synthesis of pGluHisProNH2 is typically achieved by solid-phase peptide synthesis using standard Fmoc or t-Boc strategies, with an N-terminal pyroglutamylation step to generate the blocked N terminus and a C-terminal amide to cap the peptide. The compound is used as a building block in peptide chemistry, a model substrate for enzymatic studies, and as a reference or internal standard in analytical applications such as high-performance liquid chromatography and mass spectrometry.

Applications of pGluHisProNH2 include investigation of protease specificity, studies of peptide conformational effects on receptor or enzyme binding, and use as a simple, well-defined reference peptide in analytical workflows. Its compact size and modified termini make it a convenient probe for basic peptide science.