Intramolecular Forces Density in Mesophilic and Thermophilic Proteins: Amino Acid Clusters Based Study
Abstract: Thermostability of
(hyper)thermophilic enzymes has been taken as an advantage in industry to
enhance biochemical reactions at elevated temperature. Factors responsible
for the thermostability in this class of
proteins, however, still remain unclear despite the many works that have been
done to elucidate such factors by performing various comparative studies to
homologous pairs of (hyper)thermophilic and mesophilic proteins. In the current
work, we elucidated the factors by comparing intramolecular forces density in
tertiary structure of mesophilic and (hyper)thermophilic proteins in terms of
the content of various types of amino acid clusters. A graph spectral method was
employed to probe the charged, hydrophobic and aromatic clusters in each
tertiary structure of all classes of thermophilic proteins used in our study.
Our results revealed that mesophilic and (hyper)thermophilic proteins contain similar
level of all types of amino clusters, thereby stabilized with similar
level of high-density intramolecular
forces, but the former contain a higher number of non-cluster residues and less
stabilized by electrostatic interactions, thereby more sensitive to heat.
Author: Rukman Hertadi and Minoru
Kanehisa
Journal Code: jpkimiagg070001
