![]()
AMBIENTUM BIOETHICA BIOLOGIA CHEMIA DIGITALIA DRAMATICA EDUCATIO ARTIS GYMNAST. ENGINEERING EPHEMERIDES EUROPAEA GEOGRAPHIA GEOLOGIA HISTORIA HISTORIA ARTIUM INFORMATICA IURISPRUDENTIA MATHEMATICA MUSICA NEGOTIA OECONOMICA PHILOLOGIA PHILOSOPHIA PHYSICA POLITICA PSYCHOLOGIA-PAEDAGOGIA SOCIOLOGIA THEOLOGIA CATHOLICA THEOLOGIA CATHOLICA LATIN THEOLOGIA GR.-CATH. VARAD THEOLOGIA ORTHODOXA THEOLOGIA REF. TRANSYLVAN
|
|||||||
The STUDIA UNIVERSITATIS BABEŞ-BOLYAI issue article summary The summary of the selected article appears at the bottom of the page. In order to get back to the contents of the issue this article belongs to you have to access the link from the title. In order to see all the articles of the archive which have as author/co-author one of the authors mentioned below, you have to access the link from the author's name. |
|||||||
STUDIA CHEMIA - Issue no. 4 / 2015 | |||||||
Article: |
STRUCTURAL MODELING OF PHENYLALANINE AMMONIA-LYASES AND RELATED MIO-CONTAINING ENZYMES – AN INSIGHT INTO THERMOSTABILITY AND IONIC INTERACTIONS. Authors: LÁSZLÓ POPPE. |
||||||
Abstract:
Biocatalysis and bioinformatics are powerful tools to analyze and enhance the properties of biocatalysts for industrial technologies. In this work, the three-dimensional structures of various phenylalanine ammonia-lyases and other 5-methylene-3,5-dihydro-4H-imidazol-4-one (MIO) dependent enzymes were investigated, analyzed, and constructed. The three- dimensional structures of MIO-containing aromatic ammonia-lyases and 2,3-aminomutases from the PDB database were analyzed. In several instances the structural deficiencies and inactive conformations were modified to approach the active states. The checked / modified PDB structures of the MIO-enzymes served as templates for the large scale homology modeling for phenylalanine ammonia-lyase (PAL) sequences with unknown structure. Multiple settings were tested in the modeling workflow to result in structures with intact active center, good overall protein quality and reasonable number of salt bridges. The experimental temperature optima of the investigated PALs were correlated with two common factors of thermal stability: salt bridge and disulfide bridge numbers. Our study indicate i) a moderate correlation between salt bridge numbers and temperature optima, ii) and negligible effects of disulfide bridges. The two examples which do not correlate with the others indicate the presence of other important factors contributing to thermal stability of the MIO-enzymes. The modified PDB structures can serve further molecular modeling projects such as functional studies with a QM/MM approach. Keywords: 3,5-dihydro-5-methylidene-4H-imidazol-4-one, MIO prosthetic group, homology modeling, phenylalanine ammonia-lyase, thermal stability, salt bridge
|
|||||||
![]() |
|||||||