Biology subjects

Parish, T.

Publications and source records attributed to Parish, T..

22 records · Page 2Linked to original sources

bioRxiv2018

Optimization of the DsRed fluorescent protein for use in Mycobacterium tuberculosis

ABSTRACTO_ST_ABSObjectiveC_ST_ABSWe have previously codon-optimized a number of red fluorescent proteins for use in Mycobacterium tuberculosis (mCherry, tdTomato, Turbo-635). We aimed to expand this repertoire to include DsRed, another widely used and flexible red fluorescent protein.\n\nResultsWe generated expression constructs with a full length DsRed under the control of one of three strong, constitutive promoters (Phsp60, PrpsA or PG13) for use in mycobacteria. We confirmed that full length DsRed (225 amino acids) was expressed and fluoresced brightly. In contrast to mCherry, truncated versions of DsRed lacking several amino acids at the N-terminus were not functional. Thus, we have expanded the repertoire of optimized fluorescent proteins for mycobacteria.

molecular biology↗

bioRxiv2018

Activation of 2,4-diaminoquinazoline in Mycobacterium tuberculosis by Rv3161c, a putative dioxygenase

The diaminoquinazoline series has good potency against Mycobacterium tuberculosis. Resistant isolates have mutations in Rv3161c, a putative dioxygenase. We carried out metabolite analysis on wild-type and an Rv3161c mutant strain after exposure to a diaminoquinazoline. The parental compound was found in intracellular extracts from the mutant, but not the wild-type. A metabolite consistent with a mono-hydroxylated form was identified in the wild-type. These data support the hypothesis that Rv3161c metabolizes diaminoquinazolines in M. tuberculosis.

microbiology↗

bioRxiv2018

Phenylhydrazones are active against non-replicating Mycobacterium tuberculosis

There is an urgent need for the development of shorter, simpler and more tolerable drugs to treat antibiotic tolerant populations of Mycobacterium tuberculosis. We previously identified a series of phenylhydrazones (PHY) active against M. tuberculosis. We selected six representative compounds for further analysis. All compounds were active against non-replicating M. tuberculosis, with two compounds demonstrating greater activity under hypoxic conditions than aerobic culture. Compounds had bactericidal activity with MBC/MIC of <4 and demonstrated an inoculum-dependent effect against aerobically replicating bacteria. Bacterial kill kinetics demonstrated a faster rate of kill against non-replicating bacilli generated by nutrient starvation. Compounds had limited activity against other bacterial species. In conclusion, we have demonstrated that the PHY compounds have some attractive properties in terms of their anti-tubercular activity.

microbiology↗

bioRxiv2018

Identification of cyclic hexapeptides natural products with inhibitory potency against Mycobacterium tuberculosis

A set of [~]500 purified natural product compounds was screened for inhibition against the human pathogen Mycobacterium tuberculosis. A series of cyclic hexapeptides with anti-tubercular activity was identified. Five analogs from a set of sixteen closely related compounds were active, with minimum inhibitory concentrations ranging from 2.3-8.9 M. Eleven structural analogs had no significant activity (MIC > 20 M) demonstrating structure activity relationship. Sequencing of resistant mutant isolates failed to identify changes accounting for the resistance phenotype.

microbiology↗