Verma A et al. (2016) Int J Biol Macromol "NADP(+) binding effects tryptophan accessibility, folding and stability of recombinant B. malayi G6PD."

Verma A, Siddiqi MI, Suthar MK, Chandra S, Saxena JK, Doharey PK

[Int J Biol Macromol, 2016]

Brugia malayi Glucose 6-phosphate dehydrogenase apoenzyme (BmG6PD) was expressed and purified by affinity chromatography to study the differences in kinetic properties of enzyme and the effect of the cofactor NADP(+) binding on enzyme stability. The presence of cofactor NADP(+) influenced the tertiary structure of enzyme due to significant differences in the tryptophan microenvironment. However, NADP(+) binding have no effect on secondary structure of the enzyme. Quenching with acrylamide indicated that two or more tryptophan residues became accessible upon cofactor binding. Unfolding and cross linking study of BmG6PD showed that NADP(+) stabilized the protein in presence of high concentration of urea/GdmCl. A homology model of BmG6PD constructed using human G6PD (PDB id: 2BH9) as a template indicated 34% -helix, 19% -sheet and 47% random coil conformations in the predicted model of the enzyme. In the predicted model binding of NADP(+) to BmG6PD was less tight with the structural sites (-10.96 KJ/Mol binding score) as compared with the coenzyme site (-15.47 KJ/Mol binding score).

Nicholas WL et al. (1978) Nematologica "The calorific value of C. elegans (Rhabditidae)."

Stewart AC, Nicholas WL

[Nematologica, 1978]

The calorific value of populations of Caenorhabditis elegans was measured by bomb-calorimetry. A value of 27.59 kJ per g ash-free dry weight was obtained (=6,316 calories per g). This value is high, but agrees well with calculations based on previously published analyses of lipid and glycogen reserves in Caenorhabditis sp. It is suggested that when harvested from a rich culture of bacteria Caenorhabditis has substantial lipid reserves accounting for its high calorific value.

Krishna NR et al. (2013) J Enzyme Inhib Med Chem "Physicochemical characterization of an aspin (rBm-33) from a filarial parasite Brugia malayi against the important human aspartic proteases."

Krishna NR, Gunasekaran K, Krushna NS, Rajan SS, Narayanan RB

[J Enzyme Inhib Med Chem, 2013]

The aspartic protease inhibitory efficiency of rBm-33, an aspin from a filarial parasite Brugia malayi was investigated. rBm-33 was found to be thermostable up to 90C and it forms a stable 'enzyme-product' complex with human pepsin. Aspartic protease inhibitory activity was investigated using UV spectroscopy and isothermal titration calorimetry. Our results suggest that rBm-33 inhibits the activity of important human aspartic proteases that were examined with binding constants (Kb) values between 10.23 x 10(3) and 6.52 x 10(3) M(-1). The binding reactions were enthalpy driven with Hb values between -50.99 and -46.07 kJ mol(-1). From kinetic studies, pepsin inhibition by rBm-33 was found to be linear competitive with an inhibition constant (Ki) of 2.5 (+/-0.8) nM. Because of the inhibitory efficacy of Bm-33 against important human aspartic proteases which play a vital role in immune-regulation along with other functions, Bm-33 can be projected as a drug target for the filariasis.

Gosai SJ et al. (2010) PLoS One "Automated high-content live animal drug screening using C. elegans expressing the aggregation prone serpin alpha1-antitrypsin Z."

Johnston PA, Kovatch KJ, Silverman GA, Pak SC, King DE, Long OS, Kwak JH, Luke CJ, Gosai SJ, Perlmutter DH, Lazo JS, Shun TY

[PLoS One, 2010]

The development of preclinical models amenable to live animal bioactive compound screening is an attractive approach to discovering effective pharmacological therapies for disorders caused by misfolded and aggregation-prone proteins. In general, however, live animal drug screening is labor and resource intensive, and has been hampered by the lack of robust assay designs and high throughput work-flows. Based on their small size, tissue transparency and ease of cultivation, the use of C. elegans should obviate many of the technical impediments associated with live animal drug screening. Moreover, their genetic tractability and accomplished record for providing insights into the molecular and cellular basis of human disease, should make C. elegans an ideal model system for in vivo drug discovery campaigns. The goal of this study was to determine whether C. elegans could be adapted to high-throughput and high-content drug screening strategies analogous to those developed for cell-based systems. Using transgenic animals expressing fluorescently-tagged proteins, we first developed a high-quality, high-throughput work-flow utilizing an automated fluorescence microscopy platform with integrated image acquisition and data analysis modules to qualitatively assess different biological processes including, growth, tissue development, cell viability and autophagy. We next adapted this technology to conduct a small molecule screen and identified compounds that altered the intracellular accumulation of the human aggregation prone mutant that causes liver disease in alpha1-antitrypsin deficiency. This study provides powerful validation for advancement in preclinical drug discovery campaigns by screening live C. elegans modeling alpha1-antitrypsin deficiency and other complex disease phenotypes on high-content imaging platforms.