scholarly journals A family of low molecular-weight, organic catalysts for reductive C–C bond formation

2015 ◽  
Vol 51 (73) ◽  
pp. 13902-13905 ◽  
Author(s):  
Saad Shaaban ◽  
Anaïs Jolit ◽  
Desislava Petkova ◽  
Nuno Maulide
Keyword(s):  
Molecular Weight ◽  
Ultraviolet Light ◽  
Bond Formation ◽  
Diazonium Salts ◽  
Low Molecular Weight ◽  
Organic Catalysts

Using only small amounts of a hydrazine catalyst, the coupling of diazonium salts to a variety of reactive partners has been achieved, without the requirement for either metal adjuvants or irradiation with visible or ultraviolet light.

ChemInform Abstract: A Family of Low Molecular-Weight, Organic Catalysts for Reductive C-C Bond Formation.

ChemInform ◽  
2016 ◽  
Vol 47 (1) ◽  
Author(s):  
Saad Shaaban ◽  
Anais Jolit ◽  
Desislava Petkova ◽  
Nuno Maulide
Keyword(s):  
Molecular Weight ◽  
Bond Formation ◽  
Low Molecular Weight ◽  
Organic Catalysts

scholarly journals A Relaxed Specificity in Interchain Disulfide Bond Formation Characterizes the Assembly of a Low-Molecular-Weight Glutenin Subunit in the Endoplasmic Reticulum

2008 ◽  
Vol 149 (1) ◽  
pp. 412-423 ◽  
Author(s):  
Alessio Lombardi ◽  
Alessandra Barbante ◽  
Pietro Della Cristina ◽  
Daniele Rosiello ◽  
Chiara Lara Castellazzi ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Endoplasmic Reticulum ◽  
Disulfide Bond ◽  
Bond Formation ◽  
Glutenin Subunit ◽  
Low Molecular Weight ◽  
Disulfide Bond Formation ◽  
Interchain Disulfide Bond

scholarly journals On-column disulfide bond formation of monoclonal antibodies during Protein A chromatography eliminates low molecular weight species and rescues reduced antibodies

mAbs ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 1829333
Author(s):  
Zhijun Tan ◽  
Vivekh Ehamparanathan ◽  
Tingwei Ren ◽  
Peifeng Tang ◽  
Laurel Hoffman ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Monoclonal Antibodies ◽  
Disulfide Bond ◽  
Bond Formation ◽  
Protein A ◽  
Low Molecular Weight ◽  
Disulfide Bond Formation

Recherches sur la lysogénie chez Bacillus thuringiensis et B. cereus

1978 ◽  
Vol 24 (7) ◽  
pp. 818-826 ◽  
Author(s):  
H.-W. Ackermann ◽  
W. A. Smirnoff
Keyword(s):  
Molecular Weight ◽  
Bacillus Thuringiensis ◽  
Mitomycin C ◽  
Ultraviolet Light ◽  
Low Molecular Weight ◽  
Apparent Correlation ◽  
Phage Sensitivity

Forty-eight strains of Bacillus thuringiensis and 12 strains of B. cereus were treated with ultraviolet light and mitomycin C. The former agent was the more effective inducer. Bacillus thuringiensis produces at least seven different phage particles with long, non-contractile tails. The frequencies of lysogeny and polylysogeny are 83 and 25% respectively. Morphologically defective phages occur in 25% of strains, whereas five of them produce low molecular-weight bacteriocins. One strain of B. cereus harbors "killer-particles." There is no apparent correlation between the presence of phage-like particles, phage sensitivity, and serotypes, biotypes, or the origin of B. thuringiensis strains.

scholarly journals Remarkable solvent isotope dependence on gelation strength in low molecular weight hydro-gelators

2017 ◽  
Vol 53 (10) ◽  
pp. 1719-1722 ◽  
Author(s):  
Tjalling R. Canrinus ◽  
Florian J. R. Cerpentier ◽  
Ben L. Feringa ◽  
Wesley R. Browne
Keyword(s):  
Molecular Weight ◽  
Hydrogen Bond ◽  
Bond Formation ◽  
Low Molecular Weight ◽  
Hydrogen Bond Formation ◽  
Π Stacking ◽  
Solvent Isotope

Hydrophobic/hydrophilic, π–π stacking, ionic and hydrogen bond formation interactions determine the strength of hydrogelators and here solvent deuteration and electrolyte strength impact gel melting heavily.

scholarly journals Conversion of Bacillus subtilis OhrR from a 1-Cys to a 2-Cys Peroxide Sensor

2008 ◽  
Vol 190 (17) ◽  
pp. 5738-5745 ◽  
Author(s):  
Sumarin Soonsanga ◽  
Jin-Won Lee ◽  
John D. Helmann
Keyword(s):  
Molecular Weight ◽  
Bacillus Subtilis ◽  
Disulfide Bond ◽  
Active Sites ◽  
Xanthomonas Campestris ◽  
Bond Formation ◽  
Cysteine Residue ◽  
Low Molecular Weight ◽  
Disulfide Bond Formation ◽  
Protein Dimer

ABSTRACTOhrR proteins can be divided into two groups based on their inactivation mechanism: 1-Cys (represented byBacillus subtilisOhrR) and 2-Cys (represented byXanthomonas campestrisOhrR). A conserved cysteine residue near the amino terminus is present in both groups of proteins and is initially oxidized to the sulfenic acid. TheB. subtilis1-Cys OhrR protein is subsequently inactivated by formation of a mixed-disulfide bond with low-molecular-weight thiols or by cysteine overoxidation to sulfinic and sulfonic acids. In contrast, theX. campestris2-Cys OhrR is inactivated when the initially oxidized cysteine sulfenate forms an intersubunit disulfide bond with a second Cys residue from the other subunit of the protein dimer. Here, we demonstrate that the 1-CysB. subtilisOhrR can be converted into a 2-Cys OhrR by introducing another cysteine residue in either position 120 or position 124. Like theX. campestrisOhrR protein, these mutants (G120C and Q124C) are inactivated by intermolecular disulfide bond formation. Analysis of oxidized 2-Cys variants both in vivo and in vitro indicates that intersubunit disulfide bond formation can occur simultaneously at both active sites in the protein dimer. Rapid formation of intersubunit disulfide bonds protects OhrR against irreversible overoxidation in the presence of strong oxidants much more efficiently than do the endogenous low-molecular-weight thiols.

scholarly journals PROPERTIES OF THE CAUSATIVE AGENT OF A CHICKEN TUMOR

1940 ◽  
Vol 71 (5) ◽  
pp. 619-633 ◽  
Author(s):  
Albert Claude ◽  
Alexandre Rothen
Keyword(s):  
Molecular Weight ◽  
Absorption Spectrum ◽  
Nucleic Acid ◽  
Ultraviolet Light ◽  
High Speed ◽  
Active Principle ◽  
Low Molecular Weight ◽  
Differential Centrifugation ◽  
Complete Inactivation ◽  
Tumor Agent

1. The tumor-producing fraction, isolated from Chicken Tumor I by means of differential centrifugation at high speed, has been investigated as regards its power to absorb ultraviolet light. A characteristic absorption spectrum was found, with a maximum at λ2575. The absorbing power of the material in that region was largely due to the presence of nucleic acid, or of a closely related compound. 2. Inactivation of the purified tumor fraction with ultraviolet light depressed the absorbing power of the material, especially in the region of 2600–2500Å. These changes were those which nucleic acid would present under the same conditions. 3. Inactivation of the tumor agent with acid or alkali was accompanied by decomposition of the tumor nucleoprotein and passage of free nucleic acid into solution. 4. Partial or complete inactivation of the tumor agent by heat, at 50° or 65deg;C., was attended by liberation of nucleic acid of low molecular weight. 5. The parallelism between tumor-producing activity and the integrity of the tumor ribonucleoprotein suggests that the nucleoprotein may be an essential part of the active principle.

A high-performance oil-free backing pump for electron microscopes

1978 ◽  
Vol 36 (1) ◽  
pp. 110-111
Author(s):  
G.K.W. Balkau ◽  
E. Bez ◽  
J.L. Farrant
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Hot Spots ◽  
High Performance ◽  
Carbonaceous Material ◽  
Contamination Rate ◽  
Low Molecular Weight ◽  
Principal Source ◽  
Rotary Pumps ◽  
Electron Microscopes

The earliest account of the contamination of electron microscope specimens by the deposition of carbonaceous material during electron irradiation was published in 1947 by Watson who was then working in Canada. It was soon established that this carbonaceous material is formed from organic vapours, and it is now recognized that the principal source is the oil-sealed rotary pumps which provide the backing vacuum. It has been shown that the organic vapours consist of low molecular weight fragments of oil molecules which have been degraded at hot spots produced by friction between the vanes and the surfaces on which they slide. As satisfactory oil-free pumps are unavailable, it is standard electron microscope practice to reduce the partial pressure of organic vapours in the microscope in the vicinity of the specimen by using liquid-nitrogen cooled anti-contamination devices. Traps of this type are sufficient to reduce the contamination rate to about 0.1 Å per min, which is tolerable for many investigations.

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