[Arg8]-α-Neo-Endorphin (1-8) is an eight-residue α-Neoendorphin analog with the sequence Tyr-Gly-Gly-Phe-Leu-Arg-Lys-Arg. It differs from α-Neoendorphin (1-8) by replacement of the native Tyr8 residue with arginine.

This single substitution removes an aromatic phenolic side chain and introduces an additional basic guanidinium group, making the peptide useful for studying C-terminal charge and receptor-address contributions within the neoendorphin scaffold.

Product Information

Aromatic-to-Basic Substitution at Position 8

Native α-Neoendorphin (1-8) terminates in Tyr, whereas this analog terminates in Arg. The modification changes both net charge and the chemical character of the C-terminal region while preserving the YGGFLRK sequence through position 7.

Direct comparison of the two peptides can therefore isolate the contribution of residue 8 without changing the N-terminal Leu-Enkephalin pharmacophore.

Research Applications

The peptide can support opioid structure–activity studies, receptor-binding comparisons, peptide-processing research and investigations of how basic C-terminal residues influence neoendorphin behavior.

We recommend reporting the Arg8 modification explicitly because the native and substituted 1-8 fragments are chemically distinct despite sharing seven residues.

Frequently Asked Questions

How does this analog differ from α-Neoendorphin (1-8)?

Arg replaces Tyr at residue 8.

Does it retain the Leu-Enkephalin motif?

Yes. Residues 1-5 are Tyr-Gly-Gly-Phe-Leu.

Research Use Only.