Drug Modification

Author(s):  
Hamid Reza Rezaie ◽  
Mohammadhossein Esnaashary ◽  
Abolfazl Aref arjmand ◽  
Andreas Öchsner
Keyword(s):  
2021 ◽  
Vol 42 (2) ◽  
pp. 351-357
Author(s):  
Hege Solberg ◽  
Siri Andreassen Devik ◽  
Hege Therese Bell ◽  
Daniel Horst Zeiss ◽  
Rose Mari Olsen

mBio ◽  
2017 ◽  
Vol 8 (3) ◽  
Author(s):  
Matthew J. Belousoff ◽  
Zohar Eyal ◽  
Mazdak Radjainia ◽  
Tofayel Ahmed ◽  
Rebecca S. Bamert ◽  
...  

ABSTRACT An unorthodox, surprising mechanism of resistance to the antibiotic linezolid was revealed by cryo-electron microscopy (cryo-EM) in the 70S ribosomes from a clinical isolate of Staphylococcus aureus. This high-resolution structural information demonstrated that a single amino acid deletion in ribosomal protein uL3 confers linezolid resistance despite being located 24 Å away from the linezolid binding pocket in the peptidyl-transferase center. The mutation induces a cascade of allosteric structural rearrangements of the rRNA that ultimately results in the alteration of the antibiotic binding site. IMPORTANCE The growing burden on human health caused by various antibiotic resistance mutations now includes prevalent Staphylococcus aureus resistance to last-line antimicrobial drugs such as linezolid and daptomycin. Structure-informed drug modification represents a frontier with respect to designing advanced clinical therapies, but success in this strategy requires rapid, facile means to shed light on the structural basis for drug resistance (D. Brown, Nat Rev Drug Discov 14:821–832, 2015, https://doi.org/10.1038/nrd4675 ). Here, detailed structural information demonstrates that a common mechanism is at play in linezolid resistance and provides a step toward the redesign of oxazolidinone antibiotics, a strategy that could thwart known mechanisms of linezolid resistance. IMPORTANCE The growing burden on human health caused by various antibiotic resistance mutations now includes prevalent Staphylococcus aureus resistance to last-line antimicrobial drugs such as linezolid and daptomycin. Structure-informed drug modification represents a frontier with respect to designing advanced clinical therapies, but success in this strategy requires rapid, facile means to shed light on the structural basis for drug resistance (D. Brown, Nat Rev Drug Discov 14:821–832, 2015, https://doi.org/10.1038/nrd4675 ). Here, detailed structural information demonstrates that a common mechanism is at play in linezolid resistance and provides a step toward the redesign of oxazolidinone antibiotics, a strategy that could thwart known mechanisms of linezolid resistance.


2000 ◽  
Vol 44 (1) ◽  
pp. 39-42 ◽  
Author(s):  
I. I. Y. Ho ◽  
C. Y. Chan ◽  
A. F. B. Cheng

ABSTRACT Aminoglycoside acetyltransferase was detected inMycobacterium kansasii and M. fortuitum but not in M. avium-M. intracellulare when they were screened by a radioassay. Aminoglycoside phosphotransferase and nucleotidyltransferase activities were absent from all three species tested. Acetyltransferases from both M. kansasiiand M. fortuitum displayed relatively highKm s, all at the millimolar level, for substrates including tobramycin, neomycin, and kanamycin A. TheKm of each substrate was well above the corresponding maximum achievable level in serum. The low affinities of these enzymes for their substrates suggested that drug modification in vivo was very unlikely. Among the various substrates tested, no apparent positive correlation was found between substrate affinity and resistance level. The presence of aminoglycoside-modifying enzymes in these mycobacterial species was therefore not shown to confer resistance to aminoglycosides.


2013 ◽  
Vol 12 (01) ◽  
pp. 1250104 ◽  
Author(s):  
VICTOR WEI-KEH (WU) CHAO

Quasiclassical Trajectory (QCT) calculation for O(3P) + HD → OH + D and O(3P) + HD → OD + H at E col = 0.4–1.0 eV and 0.5–1.0 eV, respectively, on the lowest PES 1 3A″ of Kuppermann et al. has been done. Distribution p(ϑr) of azimuthal angles between the relative velocity k of the reactants and rotational angular momentum vector j′ of either OH or OD , p(φr) of polar as well as dihedral angles correlating k - k′ -j′, p(ϑr, φr), and PDDCS dependent upon the scattering angle ϑt of either OH , or OD between k and k′ of the reactants and products, respectively, are presented and discussed. The stereodynamics and isotopic mass effects at the smallest possible collision energies 0.4 eV and 0.5 eV for OH and OD , respectively, are significantly different. The significant mass effect with quotient 1/2 of H/D, at the corresponding collision threshold may be applied for the investigation of docking mechanism, drug modification and delivery.


1988 ◽  
Vol 256 (3) ◽  
pp. 733-739 ◽  
Author(s):  
V Shoshan-Barmatz

Preincubation of sarcoplasmic reticulum (SR) with propranolol or tetracaine inhibits Ca2+ accumulation and stimulates ATPase activity by more than 2-fold. This effect is obtained only when the preincubation is carried out in the presence of ATP or other nucleoside triphosphates. The (ATP + drug)-induced inhibition of Ca2+ accumulation is pH-dependent, increasing as the pH rises above 7.5. The presence of micromolar concentrations of Ca2+ or Mg2+ during the preincubation prevents the inhibitory effect of ATP plus drug on Ca2+ accumulation or ATPase activity. The (ATP + drug) modification of SR vesicles resulted in stimulation of a rapid Ca2+ efflux from passively loaded vesicles. The ATP-dependent inhibition of Ca2+ accumulation by the drug is obtained with other local anaesthetics. The drug concentration required for 50% inhibition was 0.15 mM for dibucaine and 0.4 mM for both propranolol and tetracaine, whereas it was 5 mM, 8 mM and greater than 10 mM for lidocaine, benzocaine and procaine respectively. The heavy SR vesicles were only slightly affected by the incubation with propranolol or tetracaine in the presence of ATP, but their sensitivity increased markedly after storage at 0 degrees C for 24-48 h. These results suggest that propranolol and some local anaesthetics, in the presence of ATP, stimulate Ca2+ efflux by modifying a protein factor(s) rather than the phospholipid bilayer.


2019 ◽  
Vol 27 (2) ◽  
pp. 95-98
Author(s):  
İrem AKDEMİR KALKAN ◽  
Büşra AKYOL ◽  
Fırat YILMAZ ◽  
Arzu ONAY BEŞİKCİ ◽  
Kemal Osman MEMİKOĞLU

Sign in / Sign up

Export Citation Format

Share Document