Unifying Services to Students with Complex Needs Within a Newly Amalgamated School District

This Organizational Improvement Plan (OIP) addresses the inequitable services and supports currently available to students with complex needs throughout a newly amalgamated First Nations school district. This problem of practice explores how services for students with complex needs can be unified in a way that provides equity between schools, while being responsive to individual student needs. An overview of historical and current organizational contexts is provided, and personal and organizational leadership positions and lenses are investigated. Guiding questions emerging from this problem of practice are explored, including the capacity and professional learning needs of school-based staff, physical and human resourcing needs, and resistance of school-based staff to proposed district changes. Grounded in complexity theory, current and envisioned future states are considered, exploring potential change drivers and organizational change readiness. A framework for leading the change process is reviewed from a critical transformative leadership approach, viewed through an Indigenous leadership lens. Potential solutions are discussed, along with plans on how to implement, monitor, and measure change. An implementation, evaluation, and communication plan is described, providing a framework for change through an analysis of relevant theories, research, and organizational data. Next steps and future considerations are also reviewed to ensure ongoing organizational growth. Upon implementation and institutionalization, this OIP will ensure that students with complex needs are offered programming that better meets their individualized needs, while allowing for consistent service delivery as they transition between schools within the district

Late-stage reshaping of phage-displayed libraries to macrocyclic and bicyclic landscapes using multipurpose linchpin

Genetically-encoded libraries (GEL) are increasingly used for discovery of ligands for ‘undruggable’ targets that cannot be addressed with small molecules. Foundational GEL platforms like phage-, yeast-, ribosome- and mRNA-display enabled display of libraries composed of 20 natural amino acids (20AA). Today, numerous strategies expand GEL beyond 20AA space by incorporating unnatural amino acids (UAA) and chemical post-translational modification (cPTM) to build linear, cyclic, and bicyclic peptides. The standard operating procedure for UAA and cPTM libraries starts from a "naïve" chemically-upgraded library with 108-1012 compounds, uses target of interest and rounds of selection to narrow down to a set of receptor binding hits. However, such approach uses zero knowledge of natural peptide-receptor interactions which already exists in libraries with 20AA space. There is currently no consensus whether ‘zero knowledge’ naïve libraries or libraries with pre-existing knowledge can offer a more effective path to discovery of molecular interactions. In this manuscript, we evaluated the feasibility of discovery of macrocyclic and bicyclic peptide from "non-zero knowledge" libraries. We approach this problem by late-stage chemical reshaping of phage-displayed landscape of 20AA binders to NS3aH1 protease. The re-shaping is performed under a novel multifunctional C2-symmetric linchpin, 3,5-bis(bromomethyl)benzaldehyde (termed KYL), that combines two electrophiles that react with thiols and aldehyde group that reacts with N-terminal amine. KYL diversified phage-displayed peptides into bicyclic architectures and delineates 2 distinct sequence populations: (i) peptides that retained binding upon bicyclization (ii) peptides that lost binding once chemically modified. Our report provides a case study for discovering advanced, chemically-upgraded macrocycles and bicycles from libraries with pre-existing knowledge. The results imply that thousands of selection campaigns completed in 20AA space, in principle, can serve for late-stage reshaping and as a starting point for discovery of advanced peptide-derived ligands

Insights into the Mechanism of Action of the Two-Peptide Lantibiotic Lacticin 3147

Lacticin 3147 is a two peptide lantibiotc (LtnA1 and LtnA2) that displays nanomolar activity against many Gram-positive bacteria. Lacticin 3147 may exert its antimicrobial effect by several mechanisms. Isothermal titration calorimetry experiments show that only LtnA1 binds to the peptidoglycan precursor lipid II, which could inhibit peptidoglycan biosynthesis. An experimentally supported model of the resulting complex suggests that the key binding partners are the C-terminus of LtnA1 and pyrophosphate of lipid II. A combination of <i>in vivo</i> and <i>in vitro</i> assays indicates that LtnA1 and LtnA2 can induce rapid membrane lysis without the need for lipid II binding. However, the presence of lipid II substantially increases the activity of lacticin 3147. Furthermore, studies with synthetic LtnA2 analogues containing either desmethyl- or oxa-lanthionine rings confirm that the precise geometry of these rings is essential for this synergistic activity

<i>Base-Catalyzed</i> Bifunctional Addition to Amides and Imides at Low Temperature. A New Pathway for Carbonyl Hydrogenation

Mono- or dideprotonation at the N–H groups of the Noyori ketone hydrogenation catalyst <i>trans</i>-[RuH₂((<i>R</i>)-BINAP)­((<i>R</i>,<i>R</i>)-dpen)] (<b>1a</b>) yields <i>trans</i>-M­[RuH₂((<i>R</i>,<i>R</i>)-HNCH(Ph)CH(Ph)NH₂)­((<i>R</i>)-BINAP)], where M = K⁺ (<b>8-K</b>) or Li⁺ (<b>8-Li</b>), or <i>trans</i>-M₂[RuH₂((<i>R</i>,<i>R</i>)-HNCH(Ph)CH(Ph)NH)­((<i>R</i>)-BINAP)], where M = Li⁺ (<b>8-M′</b>_<b>2</b>), which have unprecedented activity toward the hydrogenation of amide and imide carbonyls at low temperatures in THF-<i>d</i>₈. Details of the origins of the enantioselection for the desymmetrization of <i>meso</i>-cyclic imides by hydrogenation with <b>8-K</b> are also described herein

<i>Base-Catalyzed</i> Bifunctional Addition to Amides and Imides at Low Temperature. A New Pathway for Carbonyl Hydrogenation

Mono- or dideprotonation at the N–H groups of the Noyori ketone hydrogenation catalyst <i>trans</i>-[RuH₂((<i>R</i>)-BINAP)­((<i>R</i>,<i>R</i>)-dpen)] (<b>1a</b>) yields <i>trans</i>-M­[RuH₂((<i>R</i>,<i>R</i>)-HNCH(Ph)CH(Ph)NH₂)­((<i>R</i>)-BINAP)], where M = K⁺ (<b>8-K</b>) or Li⁺ (<b>8-Li</b>), or <i>trans</i>-M₂[RuH₂((<i>R</i>,<i>R</i>)-HNCH(Ph)CH(Ph)NH)­((<i>R</i>)-BINAP)], where M = Li⁺ (<b>8-M′</b>_<b>2</b>), which have unprecedented activity toward the hydrogenation of amide and imide carbonyls at low temperatures in THF-<i>d</i>₈. Details of the origins of the enantioselection for the desymmetrization of <i>meso</i>-cyclic imides by hydrogenation with <b>8-K</b> are also described herein

Nuclear Magnetic Resonance Solution Structures of Lacticin Q and Aureocin A53 Reveal a Structural Motif Conserved among Leaderless Bacteriocins with Broad-Spectrum Activity

Lacticin Q (LnqQ) and aureocin A53 (AucA) are leaderless bacteriocins from <i>Lactococcus lactis</i> QU5 and <i>Staphylococcus aureus</i> A53, respectively. These bacteriocins are characterized by the absence of an N-terminal leader sequence and are active against a broad range of Gram-positive bacteria. LnqQ and AucA consist of 53 and 51 amino acids, respectively, and have 47% identical sequences. In this study, their three-dimensional structures were elucidated using solution nuclear magnetic resonance and were shown to consist of four α-helices that assume a very similar compact, globular overall fold (root-mean-square deviation of 1.7 Å) with a highly cationic surface and a hydrophobic core. The structures of LnqQ and AucA resemble the shorter two-component leaderless bacteriocins, enterocins 7A and 7B, despite having low levels of sequence identity. Homology modeling revealed that the observed structural motif may be shared among leaderless bacteriocins with broad-spectrum activity against Gram-positive organisms. The elucidated structures of LnqQ and AucA also exhibit some resemblance to circular bacteriocins. Despite their similar overall fold, inhibition studies showed that LnqQ and AucA have different antimicrobial potency against the Gram-positive strains tested, suggesting that sequence disparities play a crucial role in their mechanisms of action

Genetically-Encoded Discovery of Proteolytically Stable Bicyclic Inhibitors of Morphogen NODAL

In this manuscript, we developed a Two-fold Symmetric Linchpin (TSL) that converts readily available phage display peptides libraries made of 20 common amino acids to genetically-encoded libraries of bicyclic peptides displayed on phage. TSL combines an aldehyde-reactive group and two thiol-reactive groups; it bridges two side chains of cysteine [C] with an N-terminal aldehyde group derived from the N-terminal serine [S], yielding a novel bicyclic topology that lacks a free N-terminus. Phage display libraries of SX1CX2X3X4X5X6X7C sequences, where Xi is any amino acids but Cys, were converted to a library of bicyclic TSL-[S]X1[C]X2X3X4X5X6X7[C] peptides in 45 ± 15% yield. Using this library and protein morphogen NODAL as a target, we discovered bicyclic macrocycles that specifically antagonize NODAL-induced signaling in cancer cells. At a 10 µM concentration, two discovered bicyclic peptides completely suppressed NODAL-induced phosphorylation of SMAD2 in P19 embryonic carcinoma. The TSL-[S]Y[C]KRAHKN[C] bicycle inhibited NODAL-induced proliferation of NODAL-Tky-nu ovarian carcinoma cells with apparent IC50 1 µM. The same bicycle at 10 µM concentration did not affect the growth of the control Tky-nu cells. TSL-bicycles remained stable over the course of the 72 hour-long assays in a serum-rich cell-culture medium. We further observed general stability in mouse serum and in a mixture of proteases (PronaseTM) for 33 diverse bicyclic macrocycles of different ring sizes, amino acid sequences, and cross-linker geometries. TSL-constrained peptides expand the previously reported repertoire of phage display bicyclic architectures formed by cross-linking Cys side chains. We anticipate that it will aid the discovery of proteolytically stable bicyclic inhibitors for a variety of protein targets

Structural Characterization of Cyclic Kallidin Analogues in DMSO by Nuclear Magnetic Resonance and Molecular Dynamics

none6The conformational properties in DMSO of two head-to-tail cyclic analogues of kallidin ([Lys(0)]-bradykinin, KL) as well as those of the corresponding linear peptides were studied by NMR and molecular dynamics (MD) simulations. The modifications in the sequence were introduced at position 6, resulting in the four peptides, [Tyr(6)]-KL (YKL), [Trp(6)]-KL (WKL), cyclo-([Tyr(6)]-KL) (YCKL) and cyclo-([Trp(6)]-KL) (WCKL).The linear WRL analogue was significantly more potent than kallidin on rat duodenum preparations, whereas YKL was significantly less potent. Both cyclic peptides, YCKL and WCKL displayed similar activity, lower than that of the linear analogues and also of cyclo-KL. The two linear analogues display high conformational flexibility in DMSO. In the predominant conformer, for both peptides, all three X-Pro bonds adopt a traits configuration. Three out of four conformers present in YCKL and WCKL were completely assigned. The configurations at the X-Pro bonds are the same for the two analogues. All cyclic conformers show a cis configuration in at least one X-Pro bond and always opposite configuration for the two consecutive X-Pro bonds. The NOE-restrained MID calculations resulted in the detection of several elements of secondary structure in each of the conformers. Such elements are described and their possible relevance to biological activity is discussed.noneE. SCHIEVANO; L. SILVESTRI; M. GOBBO; S. MAMMI; R. ROCCHI; E. PEGGIONSchievano, Elisabetta; Silvestri, Laura; Gobbo, Marina; Mammi, Stefano; Rocchi, Raniero; Peggion, Evarist