Linked Life Data

15311940

Source:http://linkedlifedata.com/resource/pubmed/id/15311940

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
33
pubmed:dateCreated
2004-8-17
pubmed:abstractText
New isoforms of CYP51 (sterol 14alpha-demethylase), an essential enzyme in sterol biosynthesis and primary target of azole antimycotic drugs, are found in pathogenic protists, Trypanosoma brucei(TB), T. vivax, T. cruzi, and Leishmania major. The sequences share approximately 80% amino acid identity and are approximately 25% identical to sterol 14alpha-demethylases from other biological kingdoms. Differences of residues conserved throughout the rest of the CYP51 family that align with the BC-loop and helices F and G of CYP51 from Mycobacterium tuberculosis (MT)) imply possible alterations in the topology of the active site cavity of the protozoan enzymes. CYP51 and cytochrome P450 reductase (CPR) from TB were cloned, expressed in Escherichia coli, and purified. The P450 has normal spectral features (including absolute absorbance, carbon monoxide, and ligand binding spectra), is efficiently reduced by TB and rat CPR but demonstrates altered specificity in comparison with human CYP51 toward three tested azole inhibitors, and contrary to the human, Candida albicans, and MT isoforms, reveals profound substrate preference toward obtusifoliol (turnover 5.6 min(-1)). It weakly interacts with the other known CYP51 substrates; slow lanosterol conversion predominantly produces the 14alpha-carboxyaldehyde intermediate. Although obtusifoliol specificity is typical for plant isoforms of CYP51, the set of sterol biosynthetic enzymes in the protozoan genomes together with available information about sterol composition of kinetoplastid cells suggest that the substrate preference of TBCYP51 may reflect a novel sterol biosynthetic pathway in Trypanosomatidae.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
24
pubmed:volume
43
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10789-99
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
CYP51 from Trypanosoma brucei is obtusifoliol-specific.
pubmed:affiliation
Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146, USA. galina.i.lepesheva@vanderbilt.edu
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.