Helicoverpa species are polyphagous pests, with the larval stages causing major damage to economically valuable crops such as cotton, tomato, corn, sorghum, peas, sunflower, wheat and other pulses. Over the years, Helicoverpa armigera has developed resistance to most classes of chemical insecticides, and consequently it is now largely controlled on cotton plants via the use of Bt transgenic crops that express insecticidal Cry toxins which in-turn expedited resistance development in a number of pest species including H. armigera. In a hope to provide other eco-friendly alternatives solutions to counter the effect of the pest, people have identified a number of protease inhibitors (PIs) from the domesticated capsicum species Capsicum annuum, several of which potently inhibited H. armigera gut proteases and impeded growth of H. armigera larva. With a view to explore and enhance the specific nature or properties of these PIs on the mechanism of inhibition, structural and functional characterization of these PIs are inevitable. Towards this goal, we have carried out complete 1H, 13C and 15N resonance assignments of two of these PIs, identified as IRD7 and IRD12, using a suite of 2D and 3D multi-dimensional and multi-nuclear NMR experiments.
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We acknowledge financial support from the Indian Department of Science and Technology (Indo-Australian joint project DST/INT/AUS/P-63/2015 to K.V.R.C.), UGC-faculty recharge program and DST-ECR/2017/000124 to R.P.B., Australia-India Strategic Research Fund (AISRF-1277949-197), Department of Biotechnology (DBT), Council of Scientific and Industrial Research (CSIR), Tata Institute of Fundamental Research (TIFR), and the Australian National Health & Medical Research Council (Principal Research Fellowship APP1136889 to G.F.K.). We also acknowledge the Indian National Facility of High Field NMR.
Atreya HS, Chary KVR (2002) New chemical shift signatures of bound calcium in EF-hand proteins. Curr Sci 83:1240–1245Google Scholar
Atreya HS, Sahu SC, Chary KV, Govil G (2000) A tracked approach for automated NMR assignments in proteins (TATAPRO). J Biomol NMR 17:125–136CrossRefGoogle Scholar
Barnwal RP, Chary KV (2008) An efficient method for secondary structure determination in polypeptides by NMR. Curr Sci 94:5Google Scholar
Barnwal RP, Rout AK, Chary KV, Atreya HS (2007) Rapid measurement of 3J(H N-H alpha) and 3J(N-H beta) coupling constants in polypeptides. J Biomol NMR 39:259–263CrossRefGoogle Scholar
Barnwal RP, Rout AK, Chary KVR, Atreya HS (2008) Rapid measurement of pseudocontact shifts in paramagnetic proteins by GFT NMR spectroscopy. Open Magn Reson J 1:13CrossRefGoogle Scholar
Bax A, Ikura M, Kay LE, Barbato G, Spera S (1991) Multidimensional triple resonance Nmr-spectroscopy of isotopically uniformly enriched proteins—a powerful new strategy for structure determination. Ciba F Symp 161:108–135Google Scholar
Chary KV, Govil G (2008) NMR in biological systems: from molecules to humans. Springer, New YorkCrossRefGoogle Scholar
Delaglio F, Grzesiek S, Vuister GW, Zhu G, Pfeifer J, Bax A (1995) NMRPipe: a multidimensional spectral processing system based on UNIX pipes. J Biomol NMR 6:277–293CrossRefGoogle Scholar
Tay WT et al (2013) A brave new world for an old world pest: Helicoverpa armigera (Lepidoptera: Noctuidae) in Brazil. PLoS ONE 8:e80134ADSCrossRefGoogle Scholar
Telang MA, Giri AP, Sainani MN, Gupta VS (2005) Characterization of two midgut proteinases of Helicoverpa armigera and their interaction with proteinase inhibitors. J Insect Physiol 51:513–522CrossRefGoogle Scholar