Leveraging Arylboronic Acid–Cellulose Binding as a Versatile and Scalable Approach to Hydrophobic Patterning

2021 ◽  
pp. 2101280
Author(s):  
Jeffrey W. Beard ◽  
Shannon Murty ◽  
Christina Caulkins ◽  
Amanda R. Strenk ◽  
Ethan P. Luta ◽  
...  
Keyword(s):  
Arylboronic Acid ◽  
Cellulose Binding

Arylboronic Acid-Catalyzed C-Allylation of Unprotected Oximes

2019 ◽  
Author(s):  
Juha Siitonen ◽  
Padmanabha V. Kattamuri ◽  
Muhammed Yousufuddin ◽  
Laszlo Kurti
Keyword(s):  
Total Synthesis ◽  
Acid Catalysts ◽  
Mechanistic Studies ◽  
Arylboronic Acid ◽  
Synthetic Utility ◽  
Acid Catalyzed

Unprotected keto- and aldoximes are readily <i>C</i>-allylated with allyl diisopropyl boronate in the presence of arylboronic acid catalysts to yield highly-substituted <i>N</i>-alpha-secondary (2°) and tertiary (3°) hydroxylamines. The method’s synthetic utility is demonstrated with the total synthesis of the trace alkaloid <i>N</i>-methyl-euphococcine. Preliminary experimental and computational mechanistic studies point toward the formation of a boroxine as the active allylating species.<br>

scholarly journals Spontaneous Cleavages of a Heterologous Protein, the CenA Endoglucanase of Cellulomonas fimi, in Escherichia coli

2021 ◽  
Vol 14 ◽  
pp. 117863612110246
Author(s):  
Cheuk Yin Lai ◽  
Ka Lun Ng ◽  
Hao Wang ◽  
Chui Chi Lam ◽  
Wan Keung Raymond Wong
Keyword(s):  
Escherichia Coli ◽  
Cellulolytic Bacterium ◽  
Systematic Screening ◽  
Cellulomonas Fimi ◽  
E Coli ◽  
Substrate Complex ◽  
Enzyme Substrate ◽  
Glycosylation Sites ◽  
Endogenous Proteins ◽  
Cellulose Binding

CenA is an endoglucanase secreted by the Gram-positive cellulolytic bacterium, Cellulomonas fimi, to the environment as a glycosylated protein. The role of glycosylation in CenA is unclear. However, it seems not crucial for functional activity and secretion since the unglycosylated counterpart, recombinant CenA (rCenA), is both bioactive and secretable in Escherichia coli. Using a systematic screening approach, we have demonstrated that rCenA is subjected to spontaneous cleavages (SC) in both the cytoplasm and culture medium of E. coli, under the influence of different environmental factors. The cleavages were found to occur in both the cellulose-binding (CellBD) and catalytic domains, with a notably higher occurring rate detected in the former than the latter. In CellBD, the cleavages were shown to occur close to potential N-linked glycosylation sites, suggesting that these sites might serve as ‘attributive tags’ for differentiating rCenA from endogenous proteins and the points of initiation of SC. It is hypothesized that glycosylation plays a crucial role in protecting CenA from SC when interacting with cellulose in the environment. Subsequent to hydrolysis, SC would ensure the dissociation of CenA from the enzyme-substrate complex. Thus, our findings may help elucidate the mechanisms of protein turnover and enzymatic cellulolysis.

scholarly journals A solvent-dependent chirality-switchable thia-Michael addition to α,β-unsaturated carboxylic acids using a chiral multifunctional thiourea catalyst

2020 ◽  
Vol 11 (21) ◽  
pp. 5572-5576 ◽  
Author(s):  
Noboru Hayama ◽  
Yusuke Kobayashi ◽  
Eriko Sekimoto ◽  
Anna Miyazaki ◽  
Kiyofumi Inamoto ◽  
...  
Keyword(s):  
Carboxylic Acids ◽  
Tertiary Amine ◽  
Michael Addition ◽  
Arylboronic Acid ◽  
Unsaturated Carboxylic Acids

An asymmetric thia-Michael addition of arylthiols to α,β-unsaturated carboxylic acids using a thiourea catalyst that bears arylboronic acid and tertiary amine moieties is reported.

Does the cellulose-binding module move on the cellulose surface?

Cellulose ◽  
2009 ◽  
Vol 16 (4) ◽  
pp. 587-597 ◽  
Author(s):  
Yu-San Liu ◽  
Yining Zeng ◽  
Yonghua Luo ◽  
Qi Xu ◽  
Michael E. Himmel ◽  
...  
Keyword(s):  
Cellulose Binding Module ◽  
Cellulose Binding ◽  
Cellulose Surface

Total Syntheses of Enokipodins A and B Utilizing Palladium-Catalyzed Addition of An Arylboronic Acid to An Allene

2009 ◽  
Vol 11 (6) ◽  
pp. 1441-1443 ◽  
Author(s):  
Masahiro Yoshida ◽  
Yasunobu Shoji ◽  
Kozo Shishido
Keyword(s):  
Arylboronic Acid ◽  
Total Syntheses ◽  
Palladium Catalyzed

Direct synthesis of the arylboronic acid analogues of phenylglycine via microwave-assisted four-component Ugi reaction

Tetrahedron ◽  
2014 ◽  
Vol 70 (9) ◽  
pp. 1800-1804 ◽  
Author(s):  
Ru-Ching Lian ◽  
Meng-Hsuan Lin ◽  
Pin-Hsuan Liao ◽  
Jia-Jie Fu ◽  
Meng-Ju Wu ◽  
...  
Keyword(s):  
Direct Synthesis ◽  
Ugi Reaction ◽  
Arylboronic Acid ◽  
Microwave Assisted

scholarly journals Cellulose as an inert matrix for presenting cytokines to target cells: production and properties of a stem cell factor–cellulose-binding domain fusion protein

1999 ◽  
Vol 339 (2) ◽  
pp. 429-434
Author(s):  
J. Greg DOHENY ◽  
Eric J. JERVIS ◽  
M. Marta GUARNA ◽  
R. Keith HUMPHRIES ◽  
R. Antony J. WARREN ◽  
...  
Keyword(s):  
Stem Cell ◽  
Fusion Protein ◽  
Stem Cell Factor ◽  
Direct Analysis ◽  
Binding Domain ◽  
Target Cells ◽  
Cellulose Binding Domain ◽  
Binding Characteristics ◽  
Cellulose Binding ◽  
Cellulose Surface

A chimaera of stem cell factor (SCF) and a cellulose-binding domain from the xylanase Cex (CBDCex) effectively immobilizes SCF on a cellulose surface. The fusion protein retains both the cytokine properties of SCF and the cellulose-binding characteristics of CBDCex. When adsorbed on cellulose, SCF–CBDCex is up to 7-fold more potent than soluble SCF–CBDCex and than native SCF at stimulating the proliferation of factor-dependent cell lines. When cells are incubated with cellulose-bound SCF–CBDCex, activated receptors and SCF–CBDCex co-localize on the cellulose matrix. The strong binding of SCF–CBDCex to the cellulose surface permits the effective and localized stimulation of target cells; this is potentially significant for long-term perfusion culturing of factor-dependent cells. It also permits the direct analysis of the effects of surface-bound cytokines on target cells.

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