Theoretical analysis of apical bonding in copper(II) chelates with amino acids

2009 ◽  
Vol 42 (5) ◽  
pp. 793-797 ◽  
Author(s):  
Ante Miličević ◽  
Nenad Raos
Keyword(s):  
Amino Acids ◽  
Theoretical Analysis ◽  
Bond Length ◽  
Dimethyl Sulfoxide ◽  
Coordination Polyhedron ◽  
Side Chain ◽  
Naturally Occurring ◽  
Steric Crowding ◽  
Overlapping Spheres

The interdependence between the side of apical coordination (H2O, >C=O, dimethyl sulfoxide and Cl−) and steric crowding at the apical positions was investigated for a set of 20 copper(II) bis complexes with naturally occurring amino acids. As a measure of steric crowding the overlapping volumes,V*, were used, calculated by the modified overlapping spheres method. It was found that the apically coordinated side of a complex is more hindered by the side-chain atoms. In addition, if both sides are apically coordinated, the apical bond is shorter at the more crowded side. The interdependence between the length of the apical bond and distortion of the coordination polyhedron was also studied. The apical bond length shows sigmoidal dependence on the magnitude of distortion, and is also dependent on the kind of distortion (square-pyramidal or tetrahedral).

Theoretical analysis of apical bonding in copper(II) chelates withN-substituted amino acids

2009 ◽  
Vol 43 (1) ◽  
pp. 42-47 ◽  
Author(s):  
Ante Miličević ◽  
Nenad Raos
Keyword(s):  
Amino Acids ◽  
Theoretical Analysis ◽  
Bond Length ◽  
Coordination Polyhedron ◽  
Naturally Occurring ◽  
Steric Crowding ◽  
Overlapping Spheres

The interdependence between the side of apical coordination of H2O and steric crowding at the apical positions was investigated on a set of 34 copper(II) bis-complexes withN- andN,N-substituted amino acids. As a measure of steric crowding, overlapping volumesV* were used, calculated using a modified overlapping spheres method. Steric crowding around the apically bonded ligand was the same for this set of complexes as for the copper(II) bis-complexes with naturally occurring amino acids, with the optimal occupied volume values between 1 and 1.5 Å3. The interdependence between the length of the apical bond and distortion of the coordination polyhedron was also studied. The apical bond length showed sigmoidal dependence on the magnitude of distortion.

A note on the distortion theorem

2017 ◽  
Vol 73 (5) ◽  
pp. 874-878
Author(s):  
M. S. Nickolsky
Keyword(s):  
Theoretical Analysis ◽  
Bond Length ◽  
Coordination Polyhedron ◽  
Distortion Theorem ◽  
Bond Valence ◽  
Conditional Statement ◽  
The Mean

The distortion theorem is a conditional statement that establishes the certain relations between the variation of the mean bond length and the variation of the valence of a central ion of a coordination polyhedron. It was found that in some principal cases the conditional part of the distortion theorem is not necessary. A combinatorial evaluation of the distortion theorem and a theoretical analysis of the bond length–bond valence correlation were performed. An extension of the distortion theorem is proposed.

The interaction of dimethyl sulfoxide with N-benzoyl amino acids

1981 ◽  
Vol 34 (9) ◽  
pp. 1869 ◽  
Author(s):  
CW Fong ◽  
HG Grant
Keyword(s):  
Amino Acids ◽  
Hydrogen Bonding ◽  
Dimethyl Sulfoxide ◽  
Benzene Ring ◽  
Chemical Shifts ◽  
Side Chain ◽  
Torsional Angle ◽  
Intermolecular Hydrogen Bonding ◽  
Atom Increase ◽  
Self Association

The interaction of dimethyl sulfoxide with N-benzoyl amino acids in deuterochloroform has been investigated by 13C n.m.r. spectroscopy. Examination of the chemical shifts of the benzene ring reveals that intermolecular hydrogen bonding between dimethyl sulfoxide and the amido-hydrogen atom increase the effective steric size of the amino hydrogen, resulting in an increase in the torsional angle between the benzene ring and the C(O)NHCH(R)COOH side chain. Self-association of N- benzoyl amino acids in deuterochloroform occurs largely through two COOH...O=C hydrogen bonds and does not involve intermolecular hydrogen bonding to the N-H proton.

Constructing a Syntheses Table of the Standard Amino Acid Based on the PAM250 Matrix

2011 ◽  
Vol 335-336 ◽  
pp. 1279-1284
Author(s):  
Xiao Hong Shi ◽  
Xiang Hong Wang
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Physicochemical Properties ◽  
Side Chain ◽  
Side Chains ◽  
Chemical Structures ◽  
Naturally Occurring ◽  
Standard Amino Acid ◽  
Similar Amino Acid

It is well known that there are some similarities among various naturally occurring amino acids. The standard amino acids have been grouped by their general properties and the chemical structures of their side chains. In this paper we divided the molecular weight of amino acid into two parts: backbone molecular weight Mband side chain molecular weight Ms. We naturally grouped the amino acids into two sets according to the rate of Ms/ Mb. We developed a method to construct a syntheses table to reflect the relevant physicochemical properties based on the PAM250 matrix and successfully established an elegant table of the twenty amino acids. Our work proved that PAM250 matrix could be used not only in finding reasonable alignments but also in grouping similar amino acid.

scholarly journals Molecular Basis for the Reduced Catalytic Activity of the Naturally Occurring T560M Mutant of Human 12/15-Lipoxygenase That Has Been Implicated in Coronary Artery Disease

2011 ◽  
Vol 286 (27) ◽  
pp. 23920-23927 ◽  
Author(s):  
Kathrin Schurmann ◽  
Monika Anton ◽  
Igor Ivanov ◽  
Constanze Richter ◽  
Hartmut Kuhn ◽  
...  
Keyword(s):  
Amino Acids ◽  
Hydrogen Bond ◽  
Catalytic Activity ◽  
Active Site ◽  
Side Chain ◽  
Lag Phase ◽  
Hydrogen Bond Network ◽  
Binding Partner ◽  
Naturally Occurring ◽  
Bond Network

Lipoxygenases have been implicated in cardiovascular disease. A rare single-nucleotide polymorphism causing T560M exchange has recently been described, and this mutation leads to a near null variant of the enzyme encoded for by the ALOX15 gene. When we inspected the three-dimensional structure of the rabbit ortholog, we localized Thr-560 outside the active site and identified a hydrogen bridge between its side chain and Gln-294. This interaction is part of a complex hydrogen bond network that appears to be conserved in other mammalian lipoxygenases. Gln-294 and Asn-287 are key amino acids in this network, and we hypothesized that disturbance of this hydrogen bond system causes the low activity of the T560M mutant. To test this hypothesis, we first mutated Thr-560 to amino acids not capable of forming side chain hydrogen bridges (T560M and T560A) and obtained enzyme variants with strongly reduced catalytic activity. In contrast, enzymatic activity was retained after T560S exchange. Enzyme variants with strongly reduced activity were also obtained when we mutated Gln-294 (binding partner of Thr-560) and Asn-287 (binding partner of Gln-294 and Met-418) to Leu. Basic kinetic characterization of the T560M mutant indicated that the enzyme lacks a kinetic lag phase but is rapidly inactivated. These data suggest that the low catalytic efficiency of the naturally occurring T560M mutant is caused by alterations of a hydrogen bond network interconnecting this residue with active site constituents. Disturbance of this bonding network increases the susceptibility of the enzyme for suicidal inactivation.

THEORETICAL ANALYSIS OF THE STRUCTURE AND VIBRATIONAL SPECTR OF ASPARAGINE AND GLUTAMIC AMINO ACIDS IN WATER AT DIFFERENT pH

2017 ◽  
Vol 60 (3) ◽  
pp. 094-107
Author(s):  
Galina N. Ten ◽  
◽  
N.E. Shcherbakova ◽  
Viktor I. Baranov ◽  
◽  
...  
Keyword(s):  
Amino Acids ◽  
Theoretical Analysis

13C nuclear magnetic resonance study of cyclodipeptides containing 13C enriched hydrophobic amino acids

1980 ◽  
Vol 45 (2) ◽  
pp. 482-490 ◽  
Author(s):  
Jaroslav Vičar ◽  
François Piriou ◽  
Pierre Fromageot ◽  
Karel Bláha ◽  
Serge Fermandjian
Keyword(s):  
Amino Acids ◽  
Nuclear Magnetic Resonance ◽  
Nuclear Magnetic Resonance Study ◽  
Coupling Constants ◽  
Side Chain ◽  
Amino Acid Residues ◽  
Magnetic Resonance Study ◽  
Side Chain Conformation ◽  
13C Nuclear Magnetic Resonance ◽  
Hydrophobic Amino Acids

The diastereoisomeric pairs of cyclodipeptides cis- and trans-cyclo(Ala-Ala), cyclo(Ala-Phe), cyclo(Val-Val) and cyclo(Leu-Leu) containing 85% 13C enriched amino-acid residues were synthesized and their 13C-13C coupling constants were measured. The combination of 13C-13C and 1H-1H coupling constants enabled to estimate unequivocally the side chain conformation of the valine and leucine residues.

Access to 2-Arylquinazolines via Catabolism/Reconstruction of Amino Acids with Insertion of Dimethyl Sulfoxide

2021 ◽  
Author(s):  
Jin-Tian Ma ◽  
Li-Sheng Wang ◽  
Zhi Chai ◽  
Xin-Feng Chen ◽  
Bo-Cheng Tang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Dimethyl Sulfoxide ◽  
Nitrogen Source ◽  
Carbon And Nitrogen ◽  
First Time

Quinazoline skeletons are synthesized by amino acids catabolism/reconstruction combined with dimethyl sulfoxide insertion/cyclization for the first time. The amino acid acts as a carbon and nitrogen source through HI-mediated catabolism...

Sign in / Sign up

Export Citation Format

Share Document