Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:2.7.11.8 (
FAST
)
758
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Cytochrome P-450 and NADPH-cytochrome P-450 REDUctase, both purified from liver microsomes of phenobarbital-pretreated rabbits, have been incorporated into the membrane of phosphoaditylcholine vesicles by the cholate dialysis method. The reduction of cytochrome P-450 by NADPH in this system is biphasic, consisting of two first-order reactions. The rate constant of the fast phase, in which 80--90% of the total
cytochrome
is reduced, increases as the molar ratio of the reductase to the
cytochrome
is increased at a fixed ratio of the
cytochrome
to phosphatidylcholine, suggesting that the rate-limiting step of the fast phase is the interaction between the reductase and the
cytochrome
. The rate constant of the fast phase also increases when the amount of phosphatidylcholine, relative to those of the two proteins, is decreased. This latter observation suggests that the interaction between the two proteins is effected by their random collision caused by their lateral mobilities on the plane of the membrane of phosphatidylcholine vesicles. The rate constant of the slow phase as well as the fraction of cytochrome P-450 reducible in the slow phase, on the other hand, remains essentially constant even upon alteration in the ratio of the reductase to the
cytochrome
or in that of the two proteins to phosphatidylcholine. No satisfactory explanation is as yet available for the cause of the slow-phase reduction of cytochrome P-450. The overall activity of benzphetamine N-demethylation catalyzed by the reconstituted vesicles responds to changes in the composition of the sysTEM IN A SIMILAR WAY TO THE
FAST
-PHASE REDUCTION OF CYTOCHROME P-450, though the latter is not the rate-limiting step of the overall reaction.
...
PMID:Interaction between NADPH-cytochrome P-450 reductase and cytochrome P-450 in the membrane of phosphatidylcholine vesicles. 10 85
Telavancin (TD-6424), a semisynthetic lipoglycopeptide vancomycin-derivative, is a novel antimicrobial agent developed by Theravance for overcoming resistant Gram-positive bacterial infections, specifically methicillin-resistant
Staphylococcus aureus
(MRSA). The US Food and Drug Administration (USFDA) had approved telavancin in 2009 for the treatment of complicated skin and skin structure infections (cSSSIs) caused by Gram-positive bacteria, including MRSA (
S. aureus, Streptococcus agalactiae, Streptococcus pyogenes, Streptococcus anginosus
group, or
Enterococcus faecalis
). Telavancin has two proposed mechanisms of action.
In vitro
, telavancin has a rapid, concentration-dependent bactericidal effect, due to disruption of cell membrane integrity. Telavancin has demonstrable
in vitro
activity against aerobic and anaerobic Gram-positive bacteria. Telavancin and vancomycin have similar spectra of activity. Gram-negative bacteria are usually non-susceptible to telavancin. Telavancin has been successfully tested in various animal models of bacteremia, endocarditis, meningitis, and pneumonia. Phase II Telavancin versus Standard Therapy for Treatment of Complicated Skin and Soft-Tissue Infections due to Gram-Positive Bacteria (
FAST
1 and
FAST
2) and phase III [Assessment of Telavancin in Complicated Skin and Skin Structure Infections 1 (ATLAS 1 and ATLAS 2)] clinical trials have been conducted for evaluating telavancin's efficacy and safety in cSSSIs. Phase III clinical trials have been carried out for evaluating telavancin's safety and efficacy in nosocomial pneumonia [Assessment of Telavancin for Treatment of Hospital acquired Pneumonia 1 and 2 (ATTAIN 1 and ATTAIN 2)]. A phase II randomized, double-blind, clinical trial has been carried out for evaluating telavancin's safety and efficacy in uncomplicated
S. aureus
bacteremia [Telavancin for Treatment of Uncomplicated
S. aureus
Bacteremia (ASSURE)]. Pacemaker lead-related infective endocarditis due to a vancomycin intermediate
S. aureus
(VISA) strain (non-daptomycin susceptible) was successfully treated with parenteral telavancin for 8 weeks. Telavancin extensively binds to serum albumin (~93%) and has a relatively small volume of distribution. Telavancin is not biotransformed by any
cytochrome
P
450
microsomal enzymes and excreted mainly in the urine. Though well-tolerated, worrisome adverse effects, including renal dysfunction and QTc prolongation are of potential concern. Given its extensive binding to plasma proteins, long half-life, and a long post-antibiotic effect, it represents a promising addition to the therapeutic armamentarium in combating infections caused by resistant Gram-positive pathogens, namely, MRSA.
...
PMID:Telavancin: a novel semisynthetic lipoglycopeptide agent to counter the challenge of resistant Gram-positive pathogens. 2966 74