scholarly journals The role of the hydroxy amino acid in the triplet sequence Asn-Xaa-Thr(Ser) for the N-glycosylation step during glycoprotein biosynthesis

1981 ◽  
Vol 195 (3) ◽  
pp. 639-644 ◽  
Author(s):  
E Bause ◽  
G Legler
Keyword(s):  
Hydrogen Bond ◽  
Amino Acid ◽  
Hydroxy Group ◽  
Catalytic Mechanism ◽  
Hydrogen Bond Donor ◽  
Hydrogen Bond Interaction ◽  
Hydrogen Bond Acceptor ◽  
Hydroxy Amino Acid ◽  
Hydroxy Amino

The catalytical role of the hydroxy amino acid in the “marker sequence” Asn-Xaa-Thr(Ser) for the N-glycosylation step of glycoprotein formation was investigated by using a series of hexapeptides derived from Tyr-Asn-Gly-Xaa-Ser-Val by substituting threonine, serine, cysteine, valine and O-methylthreonine respectively for Xaa. The results, which were obtained with calf liver microsomal fractions as enzyme source and dolichyl diphosphate di-N-acetyl [14C] chitobiose as glycosyl donor showed that the threonine-, serine- and cysteine-containing derivatives could be glycosylated, although at very different rates, whereas the valine and O-methylthreonine analogues did not work as glycosyl acceptors. Replacement of threonine by serine resulted in a 4-fold decrease in Vmax, and about a 10-fold increase in Km for glycosyl transfer. Replacement of serine by cysteine again decreased acceptor activity 2-3-fold. The various results, taken together, indicate an absolute requirement for a hydrogen-bond-donor function in the side chain of the hydroxy amino acid of the “marker sequence” and furthermore, point to a considerable influence of the structure of this amino acid on binding as well as on the glycosyl transfer itself. In order to explain the observed differences in the glycosyl-transfer rates, a model is proposed with a hydrogen-bond interaction between the amide of asparagine as the hydrogen-bond donor and the oxygen of the hydroxy group of the hydroxy amino acid as the hydrogen-bond acceptor. The participation of the hydroxy group in the catalytic mechanism of glycosyl transfer in the kind of proton-relay system is discussed.

SINGLE MOLECULE IMMOBILIZATION OF π-CONJUGATED MOLECULES ON Au USING DENDRIMER-BASED TEMPLATES

2005 ◽  
Vol 04 (04) ◽  
pp. 467-473 ◽  
Author(s):  
ABDELHAK BELAISSAOUI ◽  
HIDEO TOKUHISA ◽  
EMIKO KOYAMA ◽  
MASATOSHI KANESATO
Keyword(s):  
Hydrogen Bond ◽  
Ftir Spectroscopy ◽  
Single Molecule ◽  
Binding Constant ◽  
Hydrogen Bond Donor ◽  
Hydrogen Bond Interaction ◽  
Hydrogen Bond Acceptor ◽  
Conjugated Molecules ◽  
The Core ◽  
Conjugated Molecule

We demonstrate that immobilization of a π-conjugated molecule containing a bipyridine moiety as a hydrogen bond acceptor on Au using a dendrimer-based template with 3,4-dihydroxybenzene moiety at the core as a hydrogen bond donor. The hydrogen bond interaction was used for the linkage between the conjugated molecule and the template to improve the method to fabricate single-molecule arrays we reported before.1 Although the binding constant is small ( K = 120 ± 20 M -1) in CDCl 3, it was demonstrated that the dendrimer spacer serves as a template to isolate the π-conjugated molecule, and is removable simply with a CH 2 Cl 2 rinsing by surface FTIR spectroscopy.

scholarly journals Amino Acid-Based Deep Eutectic Solvents in Biomass Processing - Recent Advances

2021 ◽  
Author(s):  
Gustavo Gomes ◽  
Renan Mattioli ◽  
Julio Cezar Pastre
Keyword(s):  
Hydrogen Bond ◽  
Amino Acid ◽  
Choline Chloride ◽  
Deep Eutectic Solvents ◽  
Chemical Conversion ◽  
Hydrogen Bond Donor ◽  
Hydrogen Bond Acceptor ◽  
Platform Chemicals ◽  
Biomass Processing ◽  
Solvent Systems

The use of non-conventional solvent systems, such as deep eutectic solvents (DES), for biomass processing is a growing interest. DES are formed by two or more components, usually solids at room temperature, which can interact with each other via hydrogen bonding, from a hydrogen bond acceptor (HBA) and a hydrogen bond donor (HBD), resulting in a liquid phase. The most studied HBA in the literature is choline chloride with several HBD and their use have been extensively reviewed. However, other abundant and natural HBA can be successfully applied on the preparation of different DES, e.g., amino acids. These amino acid-based DES have been used in biomass pretreatment, providing the fractionation of the main macromolecular components by lignin solubilization. In addition, amino acid-based DES can be applied in biomass chemical conversion to obtaining platform chemicals such as furanic derivatives. Bearing this in mind, this review focuses on exploring the use of amino acid-based DES on biomass processing, from pretreatment to chemical conversion.

Role of the hydrogen bond donor component for a proper development of novel hydrophobic deep eutectic solvents

2019 ◽  
Vol 281 ◽  
pp. 423-430 ◽  
Author(s):  
Matteo Tiecco ◽  
Federico Cappellini ◽  
Francesco Nicoletti ◽  
Tiziana Del Giacco ◽  
Raimondo Germani ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Deep Eutectic Solvents ◽  
Hydrogen Bond Donor

Depsipeptides Communication 31. Synthesis of depsipeptides containing ?-hydroxy ?-amino acid residues

1965 ◽  
Vol 14 (11) ◽  
pp. 1954-1957
Author(s):  
G. A. Ravdel' ◽  
N. A. Krit ◽  
V. A. Oladkina ◽  
L. A. Shchukina ◽  
M. M. Shemyakin
Keyword(s):  
Amino Acid ◽  
Amino Acid Residues ◽  
Hydroxy Amino Acid ◽  
Hydroxy Amino

On the potential role of the amino nitrogen atom as a hydrogen bond acceptor in macromolecules

1998 ◽  
Vol 279 (5) ◽  
pp. 1123-1136 ◽  
Author(s):  
Ben Luisi ◽  
Modesto Orozco ◽  
Jiri Sponer ◽  
Francisco J Luque ◽  
Zippora Shakked
Keyword(s):  
Hydrogen Bond ◽  
Nitrogen Atom ◽  
Potential Role ◽  
Amino Nitrogen ◽  
Hydrogen Bond Acceptor ◽  
Amino Nitrogen Atom

6,9-Dibromo-2a,10b-diphenyl-2a,5,10,10b-tetrahydro-2H,3H-2,3,4a,10a-tetraazabenzo[g]cyclopenta[cd]azulene-1,4-dione monohydrate

2006 ◽  
Vol 62 (5) ◽  
pp. o1754-o1755
Author(s):  
Neng-Fang She ◽  
Sheng-Li Hu ◽  
Hui-Zhen Guo ◽  
An-Xin Wu
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Water Molecule ◽  
Title Compound ◽  
Supramolecular Structure ◽  
Hydrogen Bond Donor ◽  
Hydrogen Bond Acceptor ◽  
Compound C ◽  
Bifurcated Hydrogen Bond

The title compound, C24H18Br2N4O2·H2O, forms a supramolecular structure via N—H...O, O—H...O and C—H...O hydrogen bonds. In the crystal structure, the water molecule serves as a bifurcated hydrogen-bond acceptor and as a hydrogen-bond donor.

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