02021nas a2200145   4500008004100000245012200041210006900163260000800232490000600240520143500246100001701681700002001698700002501718856013201743       2017                        eng d00aAmaranthus caudatus lectin with polyproline II fold: conformational and functional transitions and molecular dynamics0 aAmaranthus caudatus lectin with polyproline II fold conformation  cJUL0 v13 aPolyproline II (PPII) fold, a peculiar structural element was detected in the Amaranthus caudatus seed lectin (ACL) based on far UV circular dichroism spectrum, conformational transitions of the lectin and a distinct isodichroic point in thermal denaturation. It was confirmed by using PolyprOnline database to estimate the percentage of amino acids contributing to PPII fold and showed the values as 13.5% and 13.9% for PROSS and XTLSSTR, respectively. Investigations of the functional and conformational transitions of ACL during thermal, pH and guanidine hydrochloride (GdnHCl) induced denaturation were carried out using biochemical and biophysical techniques and molecular dynamics (MD) simulations approach. The lectin got aggregated at 60 °C with instantaneous structural alterations. The aggregation-prone regions in ACL were predicted using online servers viz. AGGRESCAN, AmylPred, FoldAmyloid and Waltz that were represented by Visual Molecular Dynamics tools. Nine conserved regions were identified by these softwares as being ‘hot-spots’ for aggregation. MD simulation studies of the lectin at 60 °C revealed increase in radius of gyration. The loss of PPII fold in 2.0 M GdnHCl was reversible. The partially unfolded intermediate of ACL with diminished PPII fold formed at pH 1.0 was stable up to 90 °C. The polyproline II fold has been rarely detected in lectins, ACL being the second after the potato lectin.1 aYadav, Priya1 aShahane, Ganesh1 aGaikwad, Sushama, M.  uhttps://library.ncl.res.in/content/amaranthus-caudatus-lectin-polyproline-ii-fold-conformational-and-functional-transitions-and