155 research outputs found
1,5-Diphenylcarbonohydrazide N,N-dimethylformamide
In the title compound, C13H14N4O·C3H7NO, a 1,5-phenylcarbonohydrazide molecule cocrystallizes with an N,N-dimethylformamide molecule. In the 1,5-phenylcarbonohydrazide molecule, the two phenyl rings are twisted by an angle of 45.8 (5)°. Intermolecular N—H⋯O hydrogen bonds and weak intermolecular C—H⋯O interactions contribute to a supramolecular two-dimensional network in the (101) plane
Structure-function analysis of CYP719As involved in methylenedioxy bridge-formation in the biosynthesis of benzylisoquinoline alkaloids and its de novo production
Benzylisoquinoline alkaloids (BIAs) are a type of secondary metabolite with clinical application value. (S)-stylopine is a special BIA which contains methylenedioxy bridge structures. CYP719As could catalyze the methylenedioxy bridge-formation on the A or D rings of protoberberine alkaloids, while displaying significant substrate regiospecificity. To explore the substrate preference of CYP719As, we cloned and identified five CyCYP719A candidates from Corydalis yanhusuo. Two CyCYP719As (CyCYP719A39 and CyCYP719A42) with high catalytic efficiency for the methylenedioxy bridge-formation on the D or A rings were characterized, respectively. The residues (Leu 294 for CyCYP719A42 and Asp 289 for CyCYP719A39) were identified as the key to controlling the regioselectivity of CYP719As affecting the methylenedioxy bridge-formation on the A or D rings by homology modeling and mutation analysis. Furthermore, for de novo production of BIAs, CyCYP719A39, CyCYP719A42, and their mutants were introduced into the (S)-scoulerine-producing yeast to produce 32\ua0mg/L (S)-stylopine. These results lay a foundation for understanding the structure-function relationship of CYP719A-mediated methylenedioxy bridge-formation and provide yeast strains for the BIAs production by\ua0synthetic biology
Catalytic promiscuity of O-methyltransferases from Corydalis yanhusuo leading to the structural diversity of benzylisoquinoline alkaloids
O-methyltransferases play essential roles in producing structural diversity and improving the biological properties of benzylisoquinoline alkaloids (BIAs) in plants. In this study, Corydalis yanhusuo, a plant used in traditional Chinese medicine due to the analgesic effects of its BIA-active compounds, was employed to analyze the catalytic characteristics of O-methyltransferases in the formation of BIA diversity. Seven genes encoding O-methyltransferases were cloned, and functionally characterized using seven potential BIA substrates. Specifically, an O-methyltransferase (CyOMT2) with highly efficient catalytic activity of both 4′- and 6-O-methylations of 1-BIAs was found. CyOMT6 was found to perform two sequential methylations at both 9- and 2-positions of the essential intermediate of tetrahydroprotoberberines, (S)-scoulerine. Two O-methyltransferases (CyOMT5 and CyOMT7) with wide substrate promiscuity were found, with the 2-position of tetrahydroprotoberberines as the preferential catalytic site for CyOMT5 (named scoulerine 2-O-methyltransferase) and the 6-position of 1-BIAs as the preferential site for CyOMT7. In addition, results of integrated phylogenetic molecular docking analysis and site-directed mutation suggested that residues at sites 172, 306, 313, and 314 in CyOMT5 are important for enzyme promiscuity related to O-methylations at the 6- and 7-positions of isoquinoline. Cys at site 253 in CyOMT2 was proved to promote the methylation activity of the 6-position and to expand substrate scopes. This work provides insight into O-methyltransferases in producing BIA diversity in C. yanhusuo and genetic elements for producing BIAs by metabolic engineering and synthetic biology
Luminescent polyoxotungstoeuropate anion-pillared layered double hydroxides
Novel luminescent polyoxometalate anion-pillared layered
double hydroxides (LDHs) were prepared by aqueous ion exchange
of a Zn–Al LDH precursor in nitrate form with the
europium-containing polyoxotungstate anions [EuW10O36]9–,
[Eu(BW11O39)(H2O)3]6– and [Eu(PW11O39)2]11–. The host–
guest interaction has a strong influence on the nature of the
final intercalated species, as evidenced by elemental analy-
Introduction
Layered double hydroxides are an important class
of ionic lamellar solids with the general formula
[M2+
1–xM3+
x(OH)2](Am–)x/m·nH2O (M2+ = Mg2+, Zn2+,
Ni2+ etc., M3+ = Al3+, Cr3+, Ga3+ etc).[1] The positively
charged layers, containing divalent and trivalent cations in
octahedral positions, are separated by charge balancing
anions and water molecules. The water molecules are connected
to both the metal hydroxide layers and the interlayer
anions through extensive hydrogen bonding. A range of organic
or inorganic guests may be incorporated into LDHs
by either ion exchange, direct synthesis or hydrothermal reconstruction
of calcined precursors.[2,3] In particular, intercalation
chemistry has been explored with the aim of introducing
catalytically active sites and photo- and electroactive
species. Many different types of metal coordination compounds
and oxometalates have been immobilized in LDHs,
including phthalocyanines, cyanocomplexes, oxalate complexes
and polyoxometalates (POMs).[4]
The first report of LDHs containing polyoxometalates
concerned their use as exhaust gas and hydrocarbon conversion
catalysts.[5] Since then, a variety of iso- and heteropolyanions
with different nuclearities and structures (Keggin,
Dawson, Preyssler, Finke) have been incorporated into the
interlayer space of these materials.[6–18] Two factors assume
considerable importance for the successful intercalation of
polyoxometalates into an LDH compound. First, the heteropoly
species should carry sufficient charge in order to be
[a] Department of Chemistry, CICECO, University of Aveiro,
3810-193 Aveiro, Portugal
E-mail: [email protected]
[b] Department of Physics, CICECO, University of Aveiro,
3810-193 Aveiro, Portugal
© 2006 Wiley-VCH Verlag 726 GmbH & Co. KGaA, Weinheim Eur. J. Inorg. Chem. 2006, 726–734
sis, powder X-ray diffraction (XRD), infra-red (IR) and Raman
spectroscopy, solid state magic-angle spinning (MAS) 11B
and 31P NMR spectroscopy, and photoluminescence spectroscopy.FCT - POCT
Molecular Characterization of Tb, a New Approach for an Ancient Brucellaphage
Tb (Tbilisi), the reference Brucellaphage strain, was classified as a member of the Podoviridae family with icosahedral capsids (57 ± 2 nm diameter) and short tails (32 ± 3 nm long). Brucellaphage DNA was double stranded and unmethylated; its molecular size was 34.5 kilobase pairs. Some sequences were found through RAPD analysis, TA cloning technology, and structural proteins were observed by using SDS-PAGE. Thus, the results have laid the foundation for the wider use of Brucellaphage’s basic mechanisms and practical applications
LRP10 interacts with SORL1 in the intracellular vesicle trafficking pathway in non-neuronal brain cells and localises to Lewy bodies in Parkinson's disease and dementia with Lewy bodies
Loss-of-function variants in the low-density lipoprotein receptor-related protein 10 (LRP10) gene have been associated with autosomal-dominant Parkinson's disease (PD), PD dementia, and dementia with Lewy bodies (DLB). Moreover, LRP10 variants have been found in individuals diagnosed with progressive supranuclear palsy and amyotrophic lateral sclerosis. Despite this genetic evidence, little is known about the expression and function of LRP10 protein in the human brain under physiological or pathological conditions. To better understand how LRP10 variants lead to neurodegeneration, we first performed an in-depth characterisation of LRP10 expression in post-mortem brains and human-induced pluripotent stem cell (iPSC)-derived astrocytes and neurons from control subjects. In adult human brain, LRP10 is mainly expressed in astrocytes and neurovasculature but undetectable in neurons. Similarly, LRP10 is highly expressed in iPSC-derived astrocytes but cannot be observed in iPSC-derived neurons. In astrocytes, LRP10 is present at trans-Golgi network, plasma membrane, retromer, and early endosomes. Interestingly, LRP10 also partially co-localises and interacts with sortilin-related receptor 1 (SORL1). Furthermore, although LRP10 expression and localisation in the substantia nigra of most idiopathic PD and DLB patients and LRP10 variant carriers diagnosed with PD or DLB appeared unchanged compared to control subjects, significantly enlarged LRP10-positive vesicles were detected in a patient carrying the LRP10 p.Arg235Cys variant. Last, LRP10 was detected in Lewy bodies (LB) at late maturation stages in brains from idiopathic PD and DLB patients and in LRP10 variant carriers. In conclusion, high LRP10 expression in non-neuronal cells and undetectable levels in neurons of control subjects indicate that LRP10-mediated pathogenicity is initiated via cell non-autonomous mechanisms, potentially involving the interaction of LRP10 with SORL1 in vesicle trafficking pathways. Together with the specific pattern of LRP10 incorporation into mature LBs, these data support an important mechanistic role for disturbed vesicle trafficking and loss of LRP10 function in neurodegenerative diseases
Genome-Wide Association Study of Lung Adenocarcinoma in East Asia and Comparison With a European Population
Lung adenocarcinoma is the most common type of lung cancer. Known risk variants explain only a small fraction of lung adenocarcinoma heritability. Here, we conducted a two-stage genome-wide association study of lung adenocarcinoma of East Asian ancestry (21,658 cases and 150,676 controls; 54.5% never-smokers) and identified 12 novel susceptibility variants, bringing the total number to 28 at 25 independent loci. Transcriptome-wide association analyses together with colocalization studies using a Taiwanese lung expression quantitative trait loci dataset (n = 115) identified novel candidate genes, including FADS1 at 11q12 and ELF5 at 11p13. In a multi-ancestry meta-analysis of East Asian and European studies, four loci were identified at 2p11, 4q32, 16q23, and 18q12. At the same time, most of our findings in East Asian populations showed no evidence of association in European populations. In our studies drawn from East Asian populations, a polygenic risk score based on the 25 loci had a stronger association in never-smokers vs. individuals with a history of smoking (Pinteraction = 0.0058). These findings provide new insights into the etiology of lung adenocarcinoma in individuals from East Asian populations, which could be important in developing translational applications
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