Related Experiment Video
Updated: Jan 29, 2026

Author Spotlight: A Selective Luciferase-Based Assay for Monitoring ATG4B 27 Activity in Cells
Published on: June 30, 2023
Acidiphilamides A-E, Modified Peptides as Autophagy Inhibitors from an Acidophilic Actinobacterium, Streptacidiphilus
Sunghoon Hwang1, Yejin Yun2, Won Hoon Choi2
1Natural Products Research Institute, College of Pharmacy , Seoul National University , 1 Gwanak-ro , Gwanak-gu, Seoul 08826 , Republic of Korea.
Abstract:
Five new tripeptides, acidiphilamides A-E (1-5), were discovered along with two previously reported compounds, l-isoleucinamide (6) and l-valinamide (7), from Streptacidiphilus rugosus AM-16, an acidophilic actinobacterial strain isolated from acidic forest soil. The structures of 1-5 were elucidated as modified tripeptides bearing phenylalaninol or methioninol fragments with C3-C5 acyl chains based mainly on NMR and mass spectroscopic data. The absolute configurations of the amine units were established by advanced Marfey's method and GITC (2,3,4,6-tetra- O-acetyl-β-d-glucopyranosyl isothiocyanate) derivatization followed by LC/MS analysis. Acidiphilamides A and B (1 and 2), the first secondary metabolites isolated from the rare actinobacterial genus Streptacidiphilus, significantly inhibited autophagic flux but not proteasome activity in HeLa cells. These compounds appeared to block mainly the autophagosome-lysosome fusion step in the late stage of cellular autophagy.
Related Concept Videos
Autophagy
An autophagic pathway consists of a series of signaling events activated in response to diverse stress and physiological conditions such as food deprivation,...
Peptide Bonds
Eukaryotic Transcription Inhibitors
Eukaryotic transcription inhibitors usually contain two distinct domains, a...
Modified Boxplots
However, the box plot does not tell the reader about outliers - values that lie far from the center of the data. We can modify the standard box and whisker plot to identify the outliers and visualize the actual spread of the data in a sample.
Initially, we calculate the adjusted...
Dipeptidyl Peptidase 4 Inhibitors
Antihypertensive Drugs: Direct Renin Inhibitors

