Correlation between calculated molecular descriptors of excipient amino acids and experimentally observed thermal stability of lysozyme.
A quantitative structure-property relationship (QSPR) between protein stability and the physicochemical properties of excipients was investigated to enable a more rational choice of stabilizing excipients than prior knowledge. The thermal transition temperature and aggregation time were determined for lysozyme in combination with 13 different amino acids using high throughput fluorescence spectroscopy and kinetic static light scattering measurements. On the theoretical side, around 200 2D and 3D molecular descriptors were calculated based on the amino acids' chemical structure. Multivariate data analysis was applied to correlate the descriptors with the experimental results. It was possible to identify descriptors, i.e. amino acids properties, with a positive influence on either transition temperature or aggregation onset time, or both. A high number of hydrogen bond acceptor moieties was the most prominent stabilizing factor for both responses, whereas hydrophilic surface properties and high molecular mass density mostly had a positive influence on the unfolding temperature. A high partition coefficient (logP(o/w)) was identified as the most prominent destabilizing factor for both responses. The QSPR shows good correlation between calculated molecular descriptors and the measured stabilizing effect of amino acids on lysozyme.
Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark.
Helena
H
Meng-Lund
Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark.
Natascha
N
Friis
Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark.
Marco
M
van de Weert
Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark.
Jukka
J
Rantanen
University of Eastern Finland, School of Pharmacy, Yliopistonranta 1, P.O. Box 1627, FI-70211 Kuopio, Finland; University Hospital Tübingen, Dept. of Internal Medicine I, Division of Translational Gastrointestinal Oncology, Otfried-Müller-Strasse 10, 72076 Tübingen, Germany.
Antti
A
Poso
Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark. Electronic address: holger.grohganz@sund.ku.dk.
Holger
H
Grohganz
Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark.
Lene
L
Jorgensen
D020003:1-Octanol / Q000737:chemistry; D000596:Amino Acids / Q000737:chemistry*; D004355:Drug Stability; D005079:Excipients / Q000737:chemistry*; D009113:Muramidase / Q000737:chemistry*; D058767:Protein Unfolding; D021281:Quantitative Structure-Activity Relationship; D013050:Spectrometry, Fluorescence; D044366:Transition Temperature; D014867:Water / Q000737:chemistry
D000596:Amino Acids; D005079:Excipients; D014867:Water; D009113:Muramidase; D020003:1-Octanol
Amino acids; Lysozyme; Molecular descriptors; PLS regression; QSPR; Thermal stability