Title
Carboxylator: incorporating solvent-accessible surface area for identifying protein carboxylation sites.
Abstract
In proteins, glutamate (Glu) residues are transformed into γ-carboxyglutamate (Gla) residues in a process called carboxylation. The process of protein carboxylation catalyzed by γ-glutamyl carboxylase is deemed to be important due to its involvement in biological processes such as blood clotting cascade and bone growth. There is an increasing interest within the scientific community to identify protein carboxylation sites. However, experimental identification of carboxylation sites via mass spectrometry-based methods is observed to be expensive, time-consuming, and labor-intensive. Thus, we were motivated to design a computational method for identifying protein carboxylation sites. This work aims to investigate the protein carboxylation by considering the composition of amino acids that surround modification sites. With the implication of a modified residue prefers to be accessible on the surface of a protein, the solvent-accessible surface area (ASA) around carboxylation sites is also investigated. Radial basis function network is then employed to build a predictive model using various features for identifying carboxylation sites. Based on a five-fold cross-validation evaluation, a predictive model trained using the combined features of amino acid sequence (AA20D), amino acid composition, and ASA, yields the highest accuracy at 0.874. Furthermore, an independent test done involving data not included in the cross-validation process indicates that in silico identification is a feasible means of preliminary analysis. Additionally, the predictive method presented in this work is implemented as Carboxylator ( http://csb.cse.yzu.edu.tw/Carboxylator/ ), a web-based tool for identifying carboxylated proteins with modification sites in order to help users in investigating γ-glutamyl carboxylation.
Year
DOI
Venue
2011
10.1007/s10822-011-9477-2
Journal of computer-aided molecular design
Keywords
Field
DocType
Protein carboxylation,Amino acid composition,Solvent accessible surface area (ASA)
Biochemistry,Amino acid,Amino acid composition,Chemistry,Accessible surface area,Carboxylation,Protein carboxylation,Pyruvate carboxylase,In silico,Peptide sequence
Journal
Volume
Issue
ISSN
25
10
1573-4951
Citations 
PageRank 
References 
12
0.57
9
Authors
5
Name
Order
Citations
PageRank
Cheng-Tsung Lu12039.04
Shu-An Chen2854.78
Neil Arvin Bretaña31435.03
Tzu-Hsiu Cheng4241.30
Tzong-Yi Lee561737.18