Effects of Altering Aminoglycoside Structures on Bacterial Resistance Enzyme Activities

Green, Keith D.; Chen, Wenjing

doi:10.1128/aac.00312-11

Cited by 36 publications

(44 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The main biochemical factor proposed is substrate channelling (49). This hypothesis is supported by studies that have demonstrated double modification of aminoglycosides in vitro (2,18). If dual modification proves to be relevant in vivo, substrate channelling may improve the efficiency of this process and lead to improved antibiotic detoxification for the host bacterium.…”

mentioning

confidence: 50%

Small-Angle X-Ray Scattering Analysis of the Bifunctional Antibiotic Resistance Enzyme Aminoglycoside (6′) Acetyltransferase-Ie/Aminoglycoside (2″) Phosphotransferase-Ia Reveals a Rigid Solution Structure

Caldwell

Berghuis

2012

Antimicrob Agents Chemother

View full text Add to dashboard Cite

Aminoglycoside (6=) acetyltransferase-Ie/aminoglycoside (2؆) phosphotransferase-Ia [AAC(6=)-Ie/APH(2؆)-Ia] is one of the most problematic aminoglycoside resistance factors in clinical pathogens, conferring resistance to almost every aminoglycoside antibiotic available to modern medicine. Despite 3 decades of research, our understanding of the structure of this bifunctional enzyme remains limited. We used small-angle X-ray scattering (SAXS) to model the structure of this bifunctional enzyme in solution and to study the impact of substrate binding on the enzyme. It was observed that the enzyme adopts a rigid conformation in solution, where the N-terminal AAC domain is fixed to the C-terminal APH domain and not loosely tethered. The addition of acetyl-coenzyme A, coenzyme A, GDP, guanosine 5=-[␤,␥-imido]triphosphate (GMPPNP), and combinations thereof to the protein resulted in only modest changes to the radius of gyration (R G ) of the enzyme, which were not consistent with any large changes in enzyme structure upon binding. These results imply some selective advantage to the bifunctional enzyme beyond coexpression as a single polypeptide, likely linked to an improvement in enzymatic properties. We propose that the rigid structure contributes to improved electrostatic steering of aminoglycoside substrates toward the two active sites, which may provide such an advantage.

show abstract

mentioning

confidence: 50%

Small-Angle X-Ray Scattering Analysis of the Bifunctional Antibiotic Resistance Enzyme Aminoglycoside (6′) Acetyltransferase-Ie/Aminoglycoside (2″) Phosphotransferase-Ia Reveals a Rigid Solution Structure

Caldwell

Berghuis

2012

Antimicrob Agents Chemother

View full text Add to dashboard Cite

show abstract

“…AG resistance results, in great part, from the evolution or acquisition of AG-modifying enzymes (AMEs) that acetylate (AG acetyltransferases [AACs]), phosphorylate (AG phosphotransferases [APHs]), or nucleotidylate (AG nucleotidyltransferases [ANTs]) various positions on the AG scaffolds, resulting in their deactivation as antibacterials (35). To broaden their AG resistance profile, bacteria have also evolved bifunctional AMEs, including AAC(6=)-30/ AAC(6=)-Ib (46), AAC(6=)-Ie/APH(2Љ)-Ia (2, 6), AAC(3)-Ib/ AAC(6=)-Ib= (14,19,25), and ANT(3Љ)-Ii/AAC(6=)-IId (9,24).…”

mentioning

confidence: 99%

Cosubstrate Tolerance of the Aminoglycoside Resistance Enzyme Eis from Mycobacterium tuberculosis

Chen

Green

2012

Antimicrob Agents Chemother

Self Cite

View full text Add to dashboard Cite

We previously demonstrated that aminoglycoside acetyltransferases (AACs) display expanded cosubstrate promiscuity. The enhanced intracellular survival (Eis) protein of Mycobacterium tuberculosis is responsible for the resistance of this pathogen to kanamycin A in a large fraction of clinical isolates. Recently, we discovered that Eis is a unique AAC capable of acetylating multiple amine groups on a large pool of aminoglycoside (AG) antibiotics, an unprecedented property among AAC enzymes. Here, we report a detailed study of the acyl-coenzyme A (CoA) cosubstrate profile of Eis. We show that, in contrast to other AACs, Eis efficiently uses only 3 out of 15 tested acyl-CoA derivatives to modify a variety of AGs. We establish that for almost all acyl-CoAs, the number of sites acylated by Eis is smaller than the number of sites acetylated. We demonstrate that the order of n-propionylation of the AG neamine by Eis is the same as the order of its acetylation. We also show that the 6= position is the first to be npropionylated on amikacin and netilmicin. By sequential acylation reactions, we show that AGs can be acetylated after the maximum possible n-propionylation of their scaffolds by Eis. The information reported herein will advance our understanding of the multiacetylation mechanism of inactivation of AGs by Eis, which is responsible for M. tuberculosis resistance to some AGs.

show abstract

“…Letter to modification by AMEs, 7 while in other cases acylation at this position is deleterious to antibacterial activity. Those results indicated that acylation can be a good methodology to generate novel active AG variants.…”

Section: Acs Medicinal Chemistry Lettersmentioning

confidence: 99%

“…The chemical modifications of AGs by AMEs, including AG Nacetyltransferase (AACs), AG O-phosphotransferases (APHs), or AG O-nucleotidyltransferase (ANTs), lead to a decreased affinity of the modified AGs for the ribosome. While we have shown that a single chemical modification does not necessarily remove all antibacterial activity, 7,8 the existence of bifunctional AMEs, such as AAC(3)-Ib/AAC(6′)-Ib′ 9 and AAC(6′)-30/ AAC(6′)-Ib′ 10 from Pseudomonas aeruginosa, AAC(6′)-Ie/ APH(2″)-Ia from Staphylococcus aureus, 11 and ANT(3″)-Ii/ AAC(6′)-IId from Serratia marcescens, 12 capable of performing two chemical modifications on AG scaffolds, and that of the enhanced intracellular survival (Eis) 13,14 enzyme capable of multiple acetylations increase the need for new AGs capable of evading the action of AMEs. Two main strategies for circumventing the activity of AMEs on AGs consist of (1) developing inhibitors of AMEs to be used in conjunction with currently approved AGs, and (2) making small modifications on the scaffolds of known AGs to yield products that remain active against bacteria, but are no longer modified by AMEs.…”

mentioning

confidence: 99%

Synthesis and Biological Activity of Mono- and Di-N-acylated Aminoglycosides

Chandrika

Green

Houghton

2015

ACS Med. Chem. Lett.

Self Cite

View full text Add to dashboard Cite

Despite issues with oto/nephrotoxicity and bacterial resistance, aminoglycosides (AGs) remain an effective and widely used class of antibacterial agents. For decades now, efforts toward the development of novel AGs with potential to overcome some of these problems have been major research focuses. 1-N-Acylation, especially γ-amino-β-hydroxybutyrate (AHB) derivatization, has proven to be one of the most successful strategies for improving the overall properties of AGs, including their ability to avoid certain resistance mechanisms. More recently, 6′-N-acylation arose as another possible strategy to improve the properties of these drugs. In this study, we report on the glycinyl, carboxybenzyl, and AHB mono-and diderivatization at the 1-, 6′-, and/or 4‴-amines of the AGs amikacin, kanamycin A, netilmicin, sisomicin, and tobramycin. We also present the antibacterial activities and the reduced reactivity of AG-modifying enzymes (AMEs) toward these new AG derivatives, and identify the AMEs present in the bacterial strains tested.

show abstract

Effects of Altering Aminoglycoside Structures on Bacterial Resistance Enzyme Activities

Cited by 36 publications

References 33 publications

Small-Angle X-Ray Scattering Analysis of the Bifunctional Antibiotic Resistance Enzyme Aminoglycoside (6′) Acetyltransferase-Ie/Aminoglycoside (2″) Phosphotransferase-Ia Reveals a Rigid Solution Structure

Small-Angle X-Ray Scattering Analysis of the Bifunctional Antibiotic Resistance Enzyme Aminoglycoside (6′) Acetyltransferase-Ie/Aminoglycoside (2″) Phosphotransferase-Ia Reveals a Rigid Solution Structure

Cosubstrate Tolerance of the Aminoglycoside Resistance Enzyme Eis from Mycobacterium tuberculosis

Synthesis and Biological Activity of Mono- and Di-N-acylated Aminoglycosides

Contact Info

Product

Resources

About