02489nas a2200241   4500008004100000022001400041245010400055210006900159260000800228300001400236490000800250520167700258653001801935653002801953653001801981653001501999653001702014100002202031700002102053700002202074700002002096856013102116       2020                        eng d  a0141-813000aMolecular investigation of coleopteran specific alpha-amylase inhibitors from amaranthaceae members0 aMolecular investigation of coleopteran specific alphaamylase inh  cNOV  a1444-14500 v1633 a<p>alpha-Amylase inhibitors (alpha-AIs) target alpha-amylases and interfere with the carbohydrate digestion of insects. Among different classes of alpha-AIs, a knottin-type inhibitor from Amaranthus hypochondriacus (AhAI) was found to be specific against coleopteran storage pests. In this report, we have characterized three previously unidentified knottin-type alpha-AIs from various Amaranthaceae plants namely, Amaranthus hypochondriacus (AhAI2), Alternanthera sessilis (AsAI) and Chenopodium quinoa (CqAI). They contain a signal peptide, pro-peptide, and mature peptide. The mature peptides of the new alpha-AIs shared 68 to 78% identity with AhAI and have highly variable pro-peptide regions. Along with the cystine-knot fold, they showed conservation of reactive site residues. All recombinant alpha-AIs were successfully expressed in their active form and native state using an oxidative cytoplasmic environment. Inhibition studies against various amylases revealed that these inhibitors showed selective inhibition of coleopteran recombinant insect alpha-amylases viz., Tribolium castaneum, and Callosobruchus chinensis. Tribolium castaneum alpha-amylase inhibition potency was highest for AhAI2 (Ki similar to 15 mu M) followed by AsAI (Ki similar to 43 mu M) and CqAI (Ki similar to 61 mu M). Interaction analysis of these inhibitors illustrated that the reactive site of inhibitors make several non-covalent interactions with the substrate-binding pocket of coleopteran alpha-amylases. The selectivity of these inhibitors against coleopteran a-amylases highlights their potential in storage grain pest control. (C) 2020 Elsevier B.V. All rights reserved.</p>
10aalpha-amylase10aalpha-amylase inhibitor10aAmaranthaceae10aColeoptera10aKnottin-type1 aRane, Ashwini, S.1 aVenkatesh, Varun1 aJoshi, Rakesh, S.1 aGiri, Ashok, P.  uhttps://library.ncl.res.in/content/molecular-investigation-coleopteran-specific-alpha-amylase-inhibitors-amaranthaceae-members02323nas a2200265   4500008004100000022001400041245013000055210006900185260000800254300001200262490000700274520144300281653001201724653001301736653002401749653001801773653001501791653001201806653001701818100002201835700002601857700002201883700002001905856013201925       2023                        eng d  a1572-388700aDomain shuffling and site-saturation mutagenesis for the enhanced inhibitory potential of amaranthaceae α-amylase inhibitors0 aDomain shuffling and sitesaturation mutagenesis for the enhanced  cOCT  a519-5320 v423 a<p>
	Amaranthaceae a-amylase inhibitors (AAIs) are knottin-type proteins with selective inhibitory potential against coleopteran a-amylases. Their small size and remarkable stability make them exciting molecules for protein engineering to achieve superior selectivity and efficacy. In this report, we have designed a set of AAI pro- and mature peptides chimeras. Based on in silico analysis, stable AAI chimeras having a stronger affinity with target amylases were selected for characterization. In vitro studies validated that chimera of the propeptide from Chenopodium quinoa a-AI and mature peptide from Beta vulgaris a-AI possess 3, 7.6, and 4.26 fold higher inhibition potential than parental counterparts. Importantly, recombinant AAI chimera retained specificity towards target coleopteran a-amylases. In addition, to improve the inhibitory potential of AAI, we performed in silico site-saturation mutagenesis. Computational analysis followed by experimental data showed that substituting Asparagine at the 6th position with Methionine had a remarkable increase in the specific inhibition potential of Amaranthus hypochondriacus a-AI. These results provide structural-functional insights into the vitality of AAI propeptide and a potential hotspot for mutagenesis to enhance the AAI activity. Our investigation will be a toolkit for AAI's optimization and functional differentiation for future biotechnological applications.</p>
10a& alpha10a-Amylase10a-Amylase inhibitors10aAmaranthaceae10aColeoptera10aPeptide10aPest control1 aRane, Ashwini, S.1 aNair, Vineetkumar, S.1 aJoshi, Rakesh, S.1 aGiri, Ashok, P.  uhttps://library.ncl.res.in/content/domain-shuffling-and-site-saturation-mutagenesis-enhanced-inhibitory-potential-amaranthaceae