Inhibition of Golgi mannosidase II with mannostatin A analogues: synthesis, biological evaluation, and structure-activity relationship studies.
Mannostatin and aminocyclopentitetrol analogues with various substitutions at the amino function were synthesized. These compounds were tested as inhibitors of human Golgi and lysosomal alpha-mannosidases. Modification of the amine of mannostatin had only marginal effects, whereas similar modifications of aminocyclopentitetrol led to significantly improved inhibitors. Ab initio calculations and molecular docking studies were employed to rationalize the results. It was found that mannostatin and aminocyclopentitretrol could bind to Golgi alpha-mannosidase II in a similar mode to that of the known inhibitor swainsonine. However, due to the flexibility of the five-membered rings of these compounds, additional low-energy binding modes could be adopted. These binding modes may be relevant for the improved activities of the benzyl-substituted compounds. The thiomethyl moiety of mannostatin was predicted to make favorable hydrophobic interactions with Arg228 and Tyr727 that would possibly account for its greater inhibitory activity.
Li
Bing
B
Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602, USA.
Kawatkar
Sameer P
SP
George
Shaji
S
Strachan
Heather
H
Woods
Robert J
RJ
Siriwardena
Aloysius
A
Moremen
Kelley W
KW
Boons
Geert-Jan
GJ
D000588:Amines / Q000138:chemical synthesis; D000818:Animals; D019295:Computational Biology; D003198:Computer Simulation; D018360:Crystallography, X-Ray; D004330:Drosophila / Q000737:chemistry; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D006056:Golgi Apparatus / Q000201:enzymology*; D006801:Humans; D007202:Indicators and Reagents; D008247:Lysosomes / Q000201:enzymology; D008361:Mannosidases / Q000037:antagonists & inhibitors* / Q000737:chemistry; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D043323:alpha-Mannosidase / Q000037:antagonists & inhibitors
D000588:Amines; D004791:Enzyme Inhibitors; D007202:Indicators and Reagents; D008361:Mannosidases; C038829:mannosyl-oligosaccharide 1,3 - 1,6-alpha-mannosidase; D043323:alpha-Mannosidase