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. 2016 Apr 13;17(4):555.
doi: 10.3390/ijms17040555.

Linear and Branched PEIs (Polyethylenimines) and Their Property Space

Claudiu N Lungu  1 , Mircea V Diudea  2 , Mihai V Putz  3   4 , Ireneusz P Grudziński  5
Affiliations

Linear and Branched PEIs (Polyethylenimines) and Their Property Space

Claudiu N Lungu et al. Int J Mol Sci. .

Abstract

A chemical property space defines the adaptability of a molecule to changing conditions and its interaction with other molecular systems determining a pharmacological response. Within a congeneric molecular series (compounds with the same derivatization algorithm and thus the same brute formula) the chemical properties vary in a monotonic manner, i.e., congeneric compounds share the same chemical property space. The chemical property space is a key component in molecular design, where some building blocks are functionalized, i.e., derivatized, and eventually self-assembled in more complex systems, such as enzyme-ligand systems, of which (physico-chemical) properties/bioactivity may be predicted by QSPR/QSAR (quantitative structure-property/activity relationship) studies. The system structure is determined by the binding type (temporal/permanent; electrostatic/covalent) and is reflected in its local electronic (and/or magnetic) properties. Such nano-systems play the role of molecular devices, important in nano-medicine. In the present article, the behavior of polyethylenimine (PEI) macromolecules (linear LPEI and branched BPEI, respectively) with respect to the glucose oxidase enzyme GOx is described in terms of their (interacting) energy, geometry and topology, in an attempt to find the best shape and size of PEIs to be useful for a chosen (nanochemistry) purpose.

Keywords: QSAR/QSPR; branched PEI (BPEI); chemical property space; geometric descriptors; linear PEI (LPEI); molecular principal moment of inertia; topological descriptors.

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Figures

Figure 1
Figure 1
Dihedral angles of free linear polyethylenimine (LPEI) 01 C14N8, represented as a function of the atom groups; more details in the main text.
Figure 2
Figure 2
Dissimilarity of LPEI 01 vs. BPEIs in the C14N8 set (see additional material for the rest of the clusters obtained for C18N10 and C14N8 & C18N10).
Figure 3
Figure 3
Polynomial equation calculated for the dihedral angles cluster of C14N8 BPEI 04 (the “(3)” number of equation corresponds with that of the Supplementary Material).
Figure 4
Figure 4
Chemical properties variation for C14N8 L/B PEIs in the free (undocked)—(top), and in docked form—(bottom). 1—log P; 2—Connolly accessible area (Å2); 3—Connolly molecular area (Å2); 4—Molecular weight; 5—Ovality; 6—Principal moment of inertia; 7—Molar refractivity (cm3/mol); 8—Partition coefficient; 9—Topological diameter (bonds); and 10—Wiener index.
Figure 5
Figure 5
Chemical property space of C14N8 PEIs before (top) and after docking (bottom).
Figure 6
Figure 6
Chemical property space descriptors in C14N8 PEIs, before (free of docking) and after docking.
Figure 7
Figure 7
Principal moment of inertia in the C14N8 PEI series before (free of docking) and after docking.
Figure 8
Figure 8
Models of LPEI 01 C14N8 before (left) and after docking (right) at GOx binding site.
Figure 9
Figure 9
Steric energy values of GOx-LPEI complexes.
Figure 10
Figure 10
QSAR model for GOx-LPEI complex (data computed by docking).
Figure 11
Figure 11
Steric energy for GOx-L/B PEI; the energy of BPEIs (C14 and C18 groups) is represented in yellow; the energy of LPEI C14 and C18 is shown in red; the energy of LPEI C16 is represented in green.
Figure 12
Figure 12
Steric energy of GOx-L/B PEIs complex (from left to right): 1 and 6 L PEI C14 and C18 (in red); 2 to 4 and 7 to 9 represent the corresponding branched isomers B PEIs (in yellow); LPEI C16 isomer is represented in green (see also Figure 11).
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References

    1. Kirkpatrick P., Ellis C. Chemical space. Nature. 2004;432:823–865. doi: 10.1038/432823a. - DOI
    1. Ruddigkeit L., van Deursen R., Blum L.C., Reymond J.-L. Enumeration of 166 Billion Organic Small Molecules in the Chemical Universe Database GDB-17. J. Chem. Inf. Model. 2012;52:2864–2875. doi: 10.1021/ci300415d. - DOI - PubMed
    1. Funar-Timofei S., Borota A., Avram S., Ionescu D. Mapping physic-chemical property space for commercial pesticides and drugs. ChemAxon Product Calculator Plugins (log P log D pKa etc.) [(accessed on May 2012)]. Available online: https://www.chemaxon.com/library/mapping-physico-chemical-property-space...
    1. Medina-Franco J.L., Martínez-Mayorga K., Giulianotti M.A., Houghten R.A., Pinilla C. Visualization of the Chemical Space in Drug Discovery. Curr. Comput. Aided-Drug Des. 2008;4:322–333. doi: 10.2174/157340908786786010. - DOI
    1. Shelat A.A., Guy R.K. The interdependence between screening methods and screening libraries. Curr. Opin. Chem. Biol. 2007;11:244–251. doi: 10.1016/j.cbpa.2007.05.003. - DOI - PubMed

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