Multiple Complexes of Long Aliphatic <i>N</i>-Acyltransferases Lead to Synthesis of 2,6-Diacylated/2-Acyl-Substituted Glycopeptide Antibiotics, Effectively Killing Vancomycin-Resistant Enterococcus
Teicoplanin A2-2 (Tei)/A40926 is the last-line antibiotic to treat multidrug-resistant Gram-positive bacterial infections, e.g., methicillinresistant Staphylococcus aurcus (MRSA) and vancomycin-resistant enterococcus (VRE). This class of antibiotics is powered by the N-acyltransferase (NAT) Orf11*/Dbv8 through N-acylation on glucosamine at the central residue of Tei/A40926 pseudoaglycone. The NAT enzyme possesses enormous value in untapped applications; its advanced development is hampered largely due to a lack of structural information. In this report, we present eight high-resolution X-ray crystallographic unary, binary, and ternary complexes in order to decipher the molecular basis for NAT's functionality. The enzyme undergoes a multistage conformational change upon binding of acyl-CoA, thus allowing the uploading of Tei pseudoaglycone to enable the acyl-transfer reaction to take place in the occlusion between the N- and C-halves of the protein. The acyl moiety of acyl-CoA can be bulky or lengthy, allowing a large extent of diversity in new derivatives that can be formed upon its transfer. Vancomycin/synthetic acyl-N-acetyl cysteamine was not expected to be able to serve as a surrogate for an acyl acceptor/donor, respectively. Most strikingly, NAT can catalyze formation of 2-N,6-O-diacylated or C6 -> C2 acyl-substituted Tei analogues through an unusual 1,4-migration mechanism under stoichiometric/solvational reaction control, wherein selected representatives showed excellent biological activities, effectively counteracting major types (VanABC) of VRE.
[EN] FLUOROGENIC PROBES FOR MEDIUM CHAIN ACYL-COA DEHYDROGENASE ( MCAD )<br/>[FR] SONDES FLUOROGENES POUR ACYL-COA DESHYDROGENASE DES ACIDES GRAS A CHAINE MOYENNE (MCAD)
申请人:UNIV COLUMBIA
公开号:WO2007022263A1
公开(公告)日:2007-02-22
[EN] The present invention relates to compounds useful for detecting the activity of human MCAD, compounds useful for competitively inhibiting human MCAD, as well as methods of manufacture thereof . [FR] La présente invention concerne des composés convenant à la détection de l'activité du MCAD chez l'homme, des composés convenant à l'inhibition compétitive du MCAD chez l'homme, ainsi que des procédés de fabrication correspondants.