Chemical and enzymic studies on the characterization of intermediates during the removal of the 14α-methyl group in cholesterol biosynthesis. The use of 32-functionalized lanostane derivatives

Akhtar, M. Humayoun; Alexander, Kornienko; Boar, Robin B.; McGhie, J. F.; Barton, D. H. R.

doi:10.1042/bj1690449b

Cited by 80 publications

(25 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3) (Aparicio et al 2000;Brautaset et al 2000;Gil and Campelo 2002;Carmody et al 2005). This three-step oxidation process has a strong precedent in the CYP51-catalysed oxidative demethylation of sterols (Akhtar et al 1978;Lepesheva and Waterman 2007). Other members of the CYP105 family catalyse simpler hydroxylation reactions in streptomycete polyketide biosynthesis (Fig.…”

Section: Cyp105s In the Biosynthetic Pathways Of Specialized Metabolitesmentioning

confidence: 99%

CYP105-diverse structures, functions and roles in an intriguing family of enzymes inStreptomyces

Moody

Loveridge

2014

J Appl Microbiol

View full text Add to dashboard Cite

The cytochromes P450 (CYP or P450) are a large superfamily of haem-containing enzymes found in all domains of life. They catalyse a variety of complex reactions, predominantly mixed-function oxidations, often displaying highly regio- and/or stereospecific chemistry. In streptomycetes, they are predominantly associated with secondary metabolite biosynthetic pathways or with xenobiotic catabolism. Homologues of one family, CYP105, have been found in all Streptomyces species thus far sequenced. This review looks at the diverse biological functions of CYP105s and the biosynthetic/catabolic pathways they are associated with. Examples are presented showing a range of biotransformative abilities and different contexts. As biocatalysts capable of some remarkable chemistry, CYP105s have great biotechnological potential and merit detailed study. Recent developments in biotechnological applications which utilize CYP105s are described, alongside a brief overview of the benefits and drawbacks of using P450s in commercial applications. The role of CYP105s in vivo is in many cases undefined and provides a rich source for further investigation into the functions these enzymes fulfil and the metabolic pathways they participate in, in the natural environment.

show abstract

Section: Cyp105s In the Biosynthetic Pathways Of Specialized Metabolitesmentioning

confidence: 99%

CYP105-diverse structures, functions and roles in an intriguing family of enzymes inStreptomyces

Moody

Loveridge

2014

J Appl Microbiol

View full text Add to dashboard Cite

show abstract

“…Sterol 14α-demethylation, a general feature of sterol biosynthetic pathways in eukaryotes, has been known and studied for more than three decades [57-60]. At the dawn of the new millennium, the orthologous nature of the first prokaryotic CYP51-like gene in Mtb was confirmed phylogenetically [61] and biochemically [62, 63].…”

Section: Structural and Biochemical Analysis Of Individual Enzymesmentioning

confidence: 99%

The Mycobacterium tuberculosis cytochrome P450 system

Ouellet

Johnston

Montellano

2010

Archives of Biochemistry and Biophysics

View full text Add to dashboard Cite

Tuberculosis remains a leading cause of human mortality. The emergence of strains of Mycobacterium tuberculosis, the causative agent, that are resistant to the major frontline antitubercular drugs increases the urgency for the development of new therapeutic agents. Sequencing of the M. tuberculosis genome revealed the existence of twenty cytochrome P450 enzymes, some of which are potential candidates for drug targeting. The recent burst of studies reporting microarray-based gene essentiality and transcriptome analyses under in vitro, ex vivo and in vivo conditions highlight the importance of selected P450 isoforms for M. tuberculosis viability and pathogenicity. Current knowledge of the structural and biochemical properties of the M. tuberculosis P450 enzymes and their putative redox partners is reviewed, with an emphasis on findings related to their physiological function(s) as well as their potential as drug targets. KeywordsMycobacterium tuberculosis; cytochrome P450; azole drugs; CYP51; CYP121; CYP130; CYP128; FprA; cyclodipeptide; sulfolipid Tuberculosis prevalence and importanceTuberculosis (TB) 1 has been a scourge of mankind for nearly as long as recorded history exists. Egyptian mummies show evidence of skeletal decay caused by TB and have been shown to harbor Mycobacterium tuberculosis (Mtb) DNA [1]. Hippocrates, in "Of the epidemics" written in 400 BC, describes phthisis, a disease that is consistent with TB. Phthisis is the Greek work for consumption, the term by which tuberculosis was known for many centuries. In the Seventeenth Century, Paul Bunyan labeled tuberculosis the "Captain of all these Men of Death", reflecting its preeminence as a cause of infectious death [2]. TB is still with us today as a major worldwide threat.The discovery of Mtb, the causative agent of TB, was announced by Robert Koch in a famous lecture on March 24, 1882 [3]. In his lecture Koch, who received the Nobel Prize in 1905 for his discoveries, reminded his audience that one in seven human beings died of tuberculosis. The fifty years following Koch's groundbreaking work led to the development of the antituberculosis drugs that we still use to treat this disease, starting with isoniazid. The availability of effective drugs, together with improvements in economics, medicine and public health, have led to a gradual decrease in the incidence of TB in industrialized nations. However, NIH Public Access Author ManuscriptArch Biochem Biophys. Author manuscript; available in PMC 2011 January 1. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript worldwide, TB continues to be a leading cause of death, as the World Health Organization fact sheet for 2008 estimates that there were 9.2 million new TB cases in 2006, 1.7 million people died of the disease in that year, one-third of the world's population carries the latent (dormant) form of the disease, and one in ten people infected with latent Mtb bacilli will become sick with active TB in their lifetime [4]. Furthermore, TB has again become a concern in...

show abstract

“…These are followed by a mechanistically enigmatic third step that removes the carboxaldehyde as formate with concomitant loss of the 14α-hydrogen. Biochemical experiments utilizing isotopically labeled substrates have concluded that the ferric peroxo intermediate mediates the third step, but the precise mechanism remains elusive [26]. To catalyze these two mechanistically distinct reactions, the enzyme must switch between the effective use of Compound I and peroxo intermediates.…”

Section: Introductionmentioning

confidence: 99%

Spin equilibrium and O2-binding kinetics of Mycobacterium tuberculosis CYP51 with mutations in the histidine–threonine dyad

Jennings

Modi

Elenewski

et al. 2014

Journal of Inorganic Biochemistry

View full text Add to dashboard Cite

The acidic residues of the “acid–alcohol pair” in CYP51 enzymes are uniformly replaced with histidine. Herein, we adopt the Mycobacterium tuberculosis (mt) enzyme as a model system to investigate these residues’ roles in finely tuning the heme conformation, iron spin state, and formation and decay of the oxyferrous enzyme. Properties of the mtCYP51 and the T260A, T260V, and H259A mutants were interrogated using UV–Vis and resonance Raman spectroscopies. Evidence supports that these mutations induce comprehensive changes in the heme environment. The heme iron spin states are differentially sensitive to the binding of the substrate, dihydrolanosterol (DHL). DHL and clotrimazole perturb the local environments of the heme vinyl and propionate substituents. Molecular dynamics (MD) simulations of the DHL–enzyme complexes support that the observed perturbations are attributable to changes in the DHL binding mode. Furthermore, the rates of the oxyferrous formation were measured using stopped-flow methods. These studies demonstrate that both HT mutations and DHL modulate the rates of oxyferrous formation. Paradoxically, the binding rate to the H259A mutant–DHL complex was approximately four-fold that of mtCYP51, a phenomenon that is predicted to result from the creation of an additional diffusion channel from loss of the H259–E173 ion pair in the mutant. Oxyferrous enzyme auto-oxidation rates were relatively constant, with the exception of the T260V-DHL complex. MD simulations lead us to speculate that this behavior may be attributed to the distortion of the heme macrocycle by the substrate.

show abstract

Chemical and enzymic studies on the characterization of intermediates during the removal of the 14α-methyl group in cholesterol biosynthesis. The use of 32-functionalized lanostane derivatives

Cited by 80 publications

References 30 publications

CYP105-diverse structures, functions and roles in an intriguing family of enzymes inStreptomyces

CYP105-diverse structures, functions and roles in an intriguing family of enzymes inStreptomyces

The Mycobacterium tuberculosis cytochrome P450 system

Spin equilibrium and O2-binding kinetics of Mycobacterium tuberculosis CYP51 with mutations in the histidine–threonine dyad

Contact Info

Product

Resources

About