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1.
J Vet Sci ; 25(3): e48, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38834516

RESUMO

IMPORTANCE: Early diagnosis of canine pancreatitis is challenging due to non-specific clinical signs. Currently, abdominal ultrasonography and measurement of canine pancreatic lipase (cPL) have been employed for the diagnosis of pancreatitis. OBJECTIVE: Many qualitative and quantitative commercial cPL tests have been developed and used in veterinary clinics. This study aimed to compare three different methodologies SNAP cPL, Spec cPL, and Vcheck cPL tests to assess the concordance of these assays. METHODS: Fifty serum samples were collected from 36 dogs with or without pancreatitis and subjected to SNAP cPL, Spec cPL, and Vcheck cPL tests. Agreement and correlation coefficients were calculated between the test results, and correlations were determined during the management of the patients. RESULTS: The results of the three cPL assays were strongly correlated in 47/50 serum samples (94%). Cohen's kappa analysis between the Spec cPL and Vcheck cPL showed near perfect agreement (κ = 0.960, p < 0.001), SNAP cPL and Vcheck cPL (κ = 0.920, p < 0.001), and Spec cPL and SNAP cPL (κ = 0.880, p < 0.001). The correlation coefficients (r) between data from Spec cPL and Vcheck cPL tests was calculated by Spearman's correlation test (r = 0.958, p < 0.001). Furthermore, the patterns of change in serum cPL concentrations determined using Spec cPL and Vcheck cPL were significantly consistent during the monitoring period in 11 patients. CONCLUSIONS AND RELEVANCE: Our data illustrated that Spec cPL and Vcheck cPL tests are compatible for clinical use in the diagnosis and monitoring of canine pancreatitis.


Assuntos
Doenças do Cão , Lipase , Pancreatite , Animais , Cães , Lipase/sangue , Pancreatite/veterinária , Pancreatite/diagnóstico , Pancreatite/sangue , Doenças do Cão/diagnóstico , Doenças do Cão/sangue , Masculino , Feminino , Pâncreas/enzimologia
2.
J Colloid Interface Sci ; 674: 576-586, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38945025

RESUMO

Since the chiral emission of excited states is observed on carbon dots (CDs), exploration towards the design and synthesis of chiral CDs nanomaterials with circularly polarized luminescence (CPL) properties has been at a brisk pace. In this regard, the "host and guest" co-assembly strategy based on the combination of CDs and chiral templates has been of unique interest recently for its convenient operation, multicolor tunable CPL, and wide application of prepared CDs-composited materials in optoelectronic devices and information encryption. However, the existing chiral templates that match perfectly with chiral CDs exhibiting optical activity both in ground and excited states are rather scarce. In this work, we synthesize the chiral CDs that could induce the spontaneous supramolecular self-assembly of N-(9-fluorenylmethox-ycarbonyl) (Fmoc)-protected glutamic acid to form chiral hydrogels with helical nanostructure. The co-assembled hydrogels show powerful chiral template function, which not only enable chiral CDs with a luminescence dissymmetry factor (glum) up to 10-2, but also have universal chiral transfer to inserted dye molecules, realizing full-color CPL and Förster resonance energy transfer (FRET) CPL as well as the distinction between left and right circularly polarized light. This CPL-active template based on chiral CDs enriches the design scenario of chiral functionalized nanomaterials.

3.
Chemphyschem ; : e202400543, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38881499

RESUMO

(R)-(-)-Mellein, (3R,4R)-4-hydroxymellein and (3R,4S)-4-hydroxymellein obtained from fungi, i.e. from Diplodia globulosa, were investigated as a class of natural products presenting ESIPT (excited state intramolecular proton transfer) phenomenon, through fluorescence and CPL (circularly polarized luminescence). The study was preceded by the assessment of the absolute configuration through ECD and VCD (electronic and vibrational circular dichroism) spectroscopies in addition to NMR spectra. It is found that ESIPT takes place in these systems very rapidly, and no dual fluorescence has been observed. The experimental study is backed up by TD-DFT calculations of ECD and CPL spectra, plus MD dynamics to follow proton transfer in the excited state and careful analysis of the puckering dynamics of the lactone ring. Deprotonated forms of the three compounds were also investigated by the same chiroptical experimental and theoretical methods, showing how one can find in natural compounds not only biological activity but also biologically compatible sensing probes.

4.
J Vet Intern Med ; 38(3): 1465-1474, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38580455

RESUMO

BACKGROUND: It is unknown if serum concentrations of cobalamin, folate, canine pancreatic lipase immunoreactivity (cPLI), and canine trypsin-like immunoreactivity (cTLI) obtained postprandially are equivalent to measurements obtained after withholding food in dogs with suspected gastrointestinal disease. HYPOTHESIS/OBJECTIVES: Measurements of serum concentrations of cobalamin, folate, cPLI, and cTLI postprandially will be equivalent to measurements after 12 hours of withholding food in dogs with signs of chronic gastrointestinal disease. Changes observed will not alter clinical interpretation. ANIMALS: 51 client-owned dogs with signs of gastrointestinal disease. METHODS: Prospective single arm clinical trial. Serum concentrations of cobalamin, folate, cPLI and cTLI 2, 4, and 8 hours postprandially were compared by equivalence testing to values after withholding food for 12 hours (baseline). RESULTS: Mean serum cobalamin concentrations 2 hours (498.1 ± 213.1 ng/L; P = 0.024) and 4 hours (501.9 ± 207.4 ng/L; P = 0.008) postprandial were equivalent to baseline (517.3 ± 211.5 ng/L). Mean serum cTLI 2 hours (31.3 ± 14 µg/L; P < 0.001) and 4 hours (29.6 ± 13.1 µg/L; P = 0.027) postprandial were equivalent to baseline (31.1 ± 15 µg/L). Mean serum folate concentration 2 hours postprandial (15 ± 7.7 µg/L) was equivalent to baseline (13.7 ± 8.3 µg/L; P < 0.001). Equivalence could not be assessed for cPLI due to results below the lower limit of quantification. Feeding altered the clinical interpretation in 27% (cobalamin), 35% (folate), 20% (cTLI), and 12% (cPLI) of dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: The clinical interpretation for a substantial number of samples changed after feeding, therefore withholding food before sample collection is prudent.


Assuntos
Doenças do Cão , Ácido Fólico , Gastroenteropatias , Lipase , Vitamina B 12 , Animais , Cães , Doenças do Cão/sangue , Doenças do Cão/diagnóstico , Ácido Fólico/sangue , Vitamina B 12/sangue , Masculino , Lipase/sangue , Feminino , Gastroenteropatias/veterinária , Gastroenteropatias/sangue , Estudos Prospectivos , Doença Crônica/veterinária , Período Pós-Prandial , Tripsina/sangue , Pâncreas/enzimologia
5.
New Phytol ; 242(6): 2555-2569, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38594216

RESUMO

Gibberellic acid (GA) plays a central role in many plant developmental processes and is crucial for crop improvement. DELLA proteins, the core suppressors in the GA signaling pathway, are degraded by GA via the 26S proteasomal pathway to release the GA response. However, little is known about the phosphorylation-mediated regulation of DELLA proteins. In this study, we combined GA response assays with protein-protein interaction analysis to infer the connection between Arabidopsis thaliana DELLAs and the C-TERMINAL DOMAIN PHOSPHATASE-LIKE 3 (CPL3), a phosphatase involved in the dephosphorylation of RNA polymerase II. We show that CPL3 directly interacts with DELLA proteins and promotes DELLA protein stability by inhibiting its degradation by the 26S proteasome. Consequently, CPL3 negatively modulates multiple GA-mediated processes of plant development, including hypocotyl elongation, flowering time, and anthocyanin accumulation. Taken together, our findings demonstrate that CPL3 serves as a novel regulator that could improve DELLA stability and thereby participate in GA signaling transduction.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Flores , Regulação da Expressão Gênica de Plantas , Giberelinas , Ligação Proteica , Giberelinas/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Flores/crescimento & desenvolvimento , Flores/genética , Proteólise , Estabilidade Proteica , Fosfoproteínas Fosfatases/metabolismo , Fosfoproteínas Fosfatases/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Hipocótilo/crescimento & desenvolvimento , Hipocótilo/metabolismo , Transdução de Sinais , Antocianinas/metabolismo , Fosforilação
6.
Chemistry ; 30(29): e202304146, 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38687127

RESUMO

In this work a family of multidimensional (2-(1H-tetrazol-5-yl)ethyl) amino acid coordination compounds have been synthesized and thoroughly characterized. For this purpose, glycine, valine, phenylalanine and tyrosine have been selected as starting amino acids and Mn2+, Zn2+ and Cd2+ as metallic nodes. From one side, for Mn2+ based dimer magnetic resonance imaging studies have been conducted, prompted by the number and disposition of the coordinated water molecules and taking into consideration the promising future of manganese-based coordination compounds as bio-compatible substitutes to conventional Gd based contrast agents. From another side, d10 block metal-based complexes allowed exploring photoluminescence properties derived by in situ synthesized ligands. Finally, amino acid preserved structural chirality allowed us to examine chiroptical properties, particularly focusing on circularly polarized luminescence.

7.
Chemphyschem ; 25(13): e202400138, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38507137

RESUMO

Circularly polarized luminescence (CPL) materials hold significant value in various fields, including information storage, secure communication, three-dimensional displays, biological detection, and optoelectronic devices. Using the Langmuir-Schaeffer (LS) assembly technique, we successfully construct a series of large-area flexible optical ultrathin films. Impressively, the inorganic assembled ultrathin films exhibit excellent CPL optical activity covering the visible to near-infrared (NIR) region, with the luminescence asymmetry factor glum ranging from 0.59 to 0.72. Moreover, such ultrathin films also display outstanding mechanical flexibility, the optical activity of which even after 240 bending cycles shows almost no difference compared to the unbent samples. Owing to the ultra-broadband optical activity and ultra-stable optical activity of such full-inorganic assembled materials on flexible substrates, coupled with their excellent processability and outstanding mechanical flexibility, we anticipate they will find use in many fields such as communication technology and flexible optoelectronics.

8.
Adv Sci (Weinh) ; 11(18): e2307448, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38447160

RESUMO

The synthesis of a family of chiral and enantiomerically pure pyridyl-diamide (pda) ligands that upon complexation with europium [Eu(CF3SO3)3] result in chiral complexes with metal centered luminescence is reported; the sets of enantiomers giving rise to both circular dichroism (CD) and circularly polarized luminescence (CPL) signatures. The solid-state structures of these chiral metallosupramolecular systems are determined using X-ray diffraction showing that the ligand chirality is transferred from solution to the solid state. This optically favorable helical packing arrangement is confirmed by recording the CPL spectra from the crystalline assembly by using steady state and enantioselective differential chiral contrast (EDCC) CPL Laser Scanning Confocal Microscopy (CPL-LSCM) where the two enantiomers can be clearly distinguished.

9.
Int J Mol Sci ; 25(5)2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38473753

RESUMO

Regardless of the unprecedented progress in malignant melanoma treatment strategies and clinical outcomes of patients during the last twelve years, this skin cancer remains the most lethal one. We have previously documented that vitamin D and its low-calcaemic analogues enhance the anticancer activity of drugs including a classic chemotherapeutic-dacarbazine-and an antiangiogenic VEGFRs inhibitor-cediranib. In this study, we explored the response of A375 and RPMI7951 melanoma lines to CPL304110 (CPL110), a novel selective inhibitor of fibroblast growth factor receptors (FGFRs), and compared its efficacy with that of AZD4547, the first-generation FGFRs selective inhibitor. We also tested whether 1,25(OH)2D3, the active form of vitamin D, modulates the response of the cells to these drugs. CPL304110 efficiently decreased the viability of melanoma cells in both A375 and RPMI7951 cell lines, with the IC50 value below 1 µM. However, the metastatic RPMI7951 melanoma cells were less sensitive to the tested drug than A375 cells, isolated from primary tumour site. Both tested FGFR inhibitors triggered G0/G1 cell cycle arrest in A375 melanoma cells and increased apoptotic/necrotic SubG1 fraction in RPMI7951 melanoma cells. 1,25(OH)2D3 modulated the efficacy of CPL304110, by decreasing the IC50 value by more than 4-fold in A375 cell line, but not in RPMI7951 cells. Further analysis revealed that both inhibitors impact vitamin D signalling to some extent, and this effect is cell line-specific. On the other hand, 1,25(OH)2D3, have an impact on the expression of FGFR receptors and phosphorylation (FGFR-Tyr653/654). Interestingly, 1,25(OH)2D3 and CPL304110 co-treatment resulted in activation of the ERK1/2 pathway in A375 cells. Our results strongly suggested possible crosstalk between vitamin D-activated pathways and activity of FGFR inhibitors, which should be considered in further clinical studies.


Assuntos
Melanoma , Neoplasias Cutâneas , Humanos , Melanoma/metabolismo , Vitamina D/metabolismo , Receptores de Calcitriol/metabolismo , Linhagem Celular Tumoral , Neoplasias Cutâneas/patologia , Vitaminas/farmacologia , Receptores de Fatores de Crescimento de Fibroblastos , Proliferação de Células
10.
Mol Ther Nucleic Acids ; 35(1): 102145, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38435119

RESUMO

Endolysins are bacteriophage-encoded hydrolases that show high antibacterial activity and a narrow substrate spectrum. We hypothesize that an mRNA-based approach to endolysin therapy can overcome some challenges of conventional endolysin therapy, namely organ targeting and bioavailability. We show that synthetic mRNA applied to three human cell lines (HEK293T, A549, HepG2 cells) leads to expression and cytosolic accumulation of the Cpl-1 endolysin with activity against Streptococcus pneumoniae. Addition of a human lysozyme signal peptide sequence translocates the Cpl-1 to the endoplasmic reticulum leading to secretion (hlySP-sCpl-1). The pneumococcal killing effect of hlySP-sCpl-1 was enhanced by introduction of a point mutation to avoid N-linked-glycosylation. hlySP-sCpl-1N215D, collected from the culture supernatant of A549 cells 6 h post-transfection showed a significant killing effect and was active against nine pneumococcal strains. mRNA-based cytosolic Cpl-1 and secretory hlySP-sCpl-1N215D show potential for innovative treatment strategies against pneumococcal disease and, to our best knowledge, represent the first approach to mRNA-based endolysin therapy. We assume that many other bacterial pathogens could be targeted with this novel approach.

11.
Angew Chem Int Ed Engl ; 63(19): e202319874, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38372180

RESUMO

Helical nanographenes with high quantum yields and strong chiroptical responses are pivotal for developing circularly polarized luminescence (CPL) materials. Here, we present the successful synthesis of novel π-extended double [7]helicenes (ED7Hs) where two helicene units are fused at the meta- or para-position of the middle benzene ring, respectively, as the structural isomers of the reported ortho-fused ED7H. The structural geometry of these ED7Hs is clearly characterized by single-crystal X-ray analysis. Notably, this class of ED7Hs exhibits bright luminescence with high quantum yields exceeding 40 %. Through geometric regulation of two embedded [7]helicene units from ortho-, meta- to para-position, these ED7Hs display exceptional amplification in chiroptical responses. This enhancement is evident in a remarkable approximate fivefold increase in the absorbance and luminescence dissymmetry factors (gabs and glum), respectively, along with a boosted CPL brightness up to 176 M-1 cm-1, surpassing the performance of most helicene-based chiral NGs. Furthermore, DFT calculations elucidate that the geometric adjustment of two [7]helicene units allows the precise alignment of electric and magnetic transition dipole moments, leading to the observed enhancement of their chiroptical responses. This study offers an effective strategy for magnifying the CPL performance in chiral NGs, promoting their expanded application as CPL emitters.

12.
J Vet Intern Med ; 38(2): 987-994, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38363021

RESUMO

BACKGROUND: Diagnosis of pancreatitis is based on clinical signs, pancreatic lipase immunoreactivity (cPLI), and abdominal ultrasonography (AUS). Diagnostic discrepancies exist between test results which might be related to differences in the timeline for resolution of these abnormalities after pancreatic injury. HYPOTHESIS/OBJECTIVES: To evaluate disease severity, ultrasonographic findings, and serum biomarkers of pancreatitis in dogs over a period of 28-days. ANIMALS: Sixteen client-owned dogs with a clinical suspicion for acute pancreatitis based on history/physical examination, an abnormal SNAP cPLI, and ultrasonographic evidence of pancreatitis. METHODS: Prospective observational study. Clinical severity (modified clinical activity index [MCAI]), cPLI, C-reactive protein (CRP), and AUS were evaluated at days 0, 2, 7, and 28. Owner assessed overall health (OH) was noted. Dogs were stratified into baseline cPLI ≥400 µg/L vs <400 µg/L groups for reporting. RESULTS: The median CRP, MCAI, and OH were 111.9 mg/L, 10, and 4/10 respectively in the cPLI ≥400 µg/L group. The median CRP, MCAI, and OH were 58.0 mg/L, 6, and 6/10 respectively in the cPLI <400 µg/L group. None of these variables were significantly different between groups. Most dogs (4/5) in the cPLI <400 µg/L group had a history of suspected pancreatitis (ie, suspect acute on chronic disease). cPLI and MCAI rapidly decreased in dogs with a baseline cPLI ≥400 µg/L, whereas sonographic evidence of pancreatitis persisted for a longer time period. CONCLUSIONS AND CLINICAL IMPORTANCE: Ultrasonographic evidence of pancreatitis in the absence of overt clinical or biochemical abnormalities might represent a resolving injury rather than active disease.


Assuntos
Doenças do Cão , Pancreatite , Animais , Cães , Doença Aguda , Proteína C-Reativa , Doenças do Cão/diagnóstico por imagem , Lipase , Pâncreas/diagnóstico por imagem , Pancreatite/diagnóstico por imagem , Pancreatite/veterinária , Ultrassonografia/veterinária
13.
Small ; 20(14): e2308429, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37988709

RESUMO

Chiral carbon nanohoops with both high fluorescence quantum yield and large luminescence dissymmetry factor are essential to the development of circularly polarized luminescence (CPL) materials. Herein, the rational design and synthesis of a series of highly fluorescent chiral carbon nanohoops TP-[8-13]CPPs via symmetry breaking with a chiral triptycene motif is reported. Theoretical calculations revealed that breaking the symmetry of nanohoops causes a unique size-dependent localization in the highest occupied molecular orbitals (HOMOs) and the lowest unoccupied molecular obtitals (LUMOs) as the increasing of sizes, which is sharply different from those of [n]cycloparaphenylenes. Photophysical investigations demonstrated that TP-[n]CPPs display size-dependent emissions with high fluorescence quantum yields up to 92.9% for TP-[13]CPP, which is the highest value among the reported chiral conjugated carbon nanohoops. The high fluorescence quantum yields are presumably attributed to both the unique acyclic, and radial conjugations and high radiative transition rates, which are further supported by theoretical investigations. Chiroptical studies revealed that chiral TP-[n]CPPs exhibit bright CPL with CPL brightness up to 100.5 M-1 cm-1 for TP-[11]CPP due to the high fluorescence quantum yield. Importantly, the investigations revealed the intrigued size-dependent properties of TP-[n]CPPs with regards to (chir)optical properties, which follow a nice linear relationship versus 1/n. Such a nice linear relationship is not observed in other reported conjugated nanohoops including CPPs.

14.
Small ; 20(13): e2308104, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37955918

RESUMO

Next-generation medical and consumer electrical devices require soft, flexible materials. Piezoelectric materials, capable of converting mechanical stress into electrical energy, are of interest across various fields. Chiral nanostructures, with inherent chirality, have emerged as potential piezoelectric materials. Peptide-based materials, known for self-assembly and stimuli responsiveness, hold promise for the utilization of chiral nanostructures. When combined with luminescent chromophores, peptides can generate aggregation-induced chiroptical effects like Circularly Polarized Luminescence (CPL) and Circular Dichroism (CD). In this study, a chiral organogel, L,L-1 is synthesized, and its self-assembly, mechanical properties, and chiroptical features are examined. The organogel exhibits thermo-reversible and thixotropic behavior, forming fibrillar networks and 2D-sheets upon cooling. CD spectroscopy reveals aggregation-induced chirality on pyrene chromophore, resulting in CPL with glum values of 3.0 (± 0.2) × 10-3 and 3.1 (± 0.2) × 10-3 for L,L-1 and D,D-1, respectively. Notably, the 2D-sheets exhibit an enhanced piezoelectric response (d33 ≈76.0 pm V-1) compared to the fibrillar network (d33 ≈64.1 pm V-1). Introducing an electron-deficient molecule into the solution forms a Charge-transfer (CT) complex, modulating the piezoelectric response to d33 ≈52.44 pm V-1. This study offers a promising approach to optoelectronics design, presenting a chiral system with both CPL and piezoelectric responses, opening new possibilities for innovative applications.

16.
Molecules ; 28(21)2023 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-37959742

RESUMO

A series of molecules that possess two quinolines, benzoquinolines, or phenanthrolines connected in a chiral fashion by a biaryl junction along with their water-soluble derivatives was developed and characterized. The influence of the structure on the basicity of the nitrogen atoms in two heterocycles was examined and the photophysical and chiroptical switching activity of the compounds upon protonation was studied both experimentally and computationally. The results demonstrated that changes in the electronic structure of the protonated vs. neutral species, promoting a bathochromic shift of dominant electronic transitions and alternation of their character from π-to-π* to charge-transfer-type, when additionally accompanied by the high structural flexibility of a system, leading to changes in conformational preferences upon proton binding, produce particularly pronounced modifications of the spectral properties in acidic medium. The latter combined with reversibility of the read-out make some of the molecules in this series very promising multifunctional pH probes.

17.
J Integr Plant Biol ; 65(12): 2660-2671, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37867412

RESUMO

N-Hydroxypipecolic acid (NHP) is a signaling molecule crucial for systemic acquired resistance (SAR), a systemic immune response in plants that provides long-lasting and broad-spectrum protection against secondary pathogen infections. To identify negative regulators of NHP biosynthesis, we performed a forward genetic screen to search for mutants with elevated expression of the NHP biosynthesis gene FLAVIN-DEPENDENT MONOOXYGENASE 1 (FMO1). Analysis of two constitutive expression of FMO1 (cef) and one induced expression of FMO1 (ief) mutants revealed that the AIPP3-PHD2-CPL2 protein complex, which is involved in the recognition of the histone modification H3K27me3 and transcriptional repression, contributes to the negative regulation of FMO1 expression and NHP biosynthesis. Our study suggests that epigenetic regulation plays a crucial role in controlling FMO1 expression and NHP levels in plants.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Epigênese Genética , Ácidos Pipecólicos/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Fosfoproteínas Fosfatases/genética
18.
Front Immunol ; 14: 1075774, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37781366

RESUMO

Bacteriolytic enzymes are promising antibacterial agents, but they can cause a typical immune response in vivo. In this study, we used a targeted modification method for two antibacterial endolysins, Pal and Cpl-1. We identified the key immunogenic amino acids, and designed and tested new, bacteriolytic variants with altered immunogenicity. One new variant of Pal (257-259 MKS → TFG) demonstrated decreased immunogenicity while a similar mutant (257-259 MKS → TFK) demonstrated increased immunogenicity. A third variant (280-282 DKP → GGA) demonstrated significantly increased antibacterial activity and it was not cross-neutralized by antibodies induced by the wild-type enzyme. We propose this variant as a new engineered endolysin with increased antibacterial activity that is capable of escaping cross-neutralization by antibodies induced by wild-type Pal. We show that efficient antibacterial enzymes that avoid cross-neutralization by IgG can be developed by epitope scanning, in silico design, and substitutions of identified key amino acids with a high rate of success. Importantly, this universal approach can be applied to many proteins beyond endolysins and has the potential for design of numerous biological drugs.


Assuntos
Antibacterianos , Formação de Anticorpos , Epitopos , Antibacterianos/farmacologia , Proteínas , Aminoácidos
19.
Astrobiology ; 23(10): 1019-1026, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37737584

RESUMO

The enantiomeric excess (ee) of l-form amino acids found in the Murchison meteorite poses some issues about the cosmic origin of their chirality. Circular dichroism (CD) spectra of amino acids in the far-ultraviolet (FUV) at around 6.8 eV (182 nm) indicate that the circularly polarized light can induce ee through photochemical reactions. Here, we resort to ab initio calculations to extract the CD spectra up to the vacuum-ultraviolet (VUV) region (∼11 eV), and we propose a novel equation to compute the ee applicable to a wider range of light frequency than what is available to date. This allows us to show that the strength of the induced ee (|ee|) in the 10 eV VUV region is comparable to the one in the 6.8 eV FUV region. This feature is common for some key amino acids (alanine, 2-aminobutyric acid, and valine). In space, intense Lyman-α (Lyα) light of 10.2 eV is emitted from star forming regions. This study provides a theoretical basis that Lyα emitter from an early starburst in the Milky Way plays a crucial role in initiating the ee of amino acids.


Assuntos
Alanina , Aminoácidos , Aminoácidos/química , Dicroísmo Circular , Estereoisomerismo
20.
Angew Chem Int Ed Engl ; 62(38): e202308281, 2023 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-37534951

RESUMO

Efficient circularly polarized luminescence (CPL) from purely organic molecules holds great promise for applications in displays, sensing, and bioimaging. However, achieving high dissymmetry values (glum ) from organic chromophores remains a significant challenge. Herein, we present a bioinspired approach using adenosine triphosphate (ATP)-triggered supramolecular polymerization of a naphthalene diimide-derived monomer (ANSG) to induce CPL with a remarkable glum value of 1.1×10-2 . The ANSG molecules undergo a templated, chiral self-assembly through a cooperative growth mechanism in the presence of ATP, resulting in scrolled nanotubes with aggregation-induced enhanced emission (AIEE) and induced CPL. Furthermore, we demonstrate the concept of chiroptical amplification of induced CPL by efficiently amplifying asymmetry using a mixture of chiral ATP and achiral pyrophosphate. This innovative approach opens numerous opportunities in the emerging field of circularly polarized luminescence.

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