3 Biotech

, 8:68 | Cite as

Classifying nitrilases as aliphatic and aromatic using machine learning technique

  • Nikhil Sharma
  • Ruchi Verma
  • Savitri
  • Tek Chand BhallaEmail author
Original Article


ProCos (Protein Composition Server, script version), one of the machine learning techniques, was used to classify nitrilases as aliphatic and aromatic nitrilases. Some important feature vectors were used to train the algorithm, which included pseudo-amino acid composition (PAAC) and five-factor solution score (5FSS). This clearly differentiated into two groups of nitrilases, i.e., aliphatic and aromatic, achieving maximum sensitivity of 100.00%, specificity of 90.00%, accuracy of 95.00% and Mathew Correlation Coefficient (MCC) of about 0.90 for the pseudo-amino acid composition. On the other hand, five-factor solution score achieved a sensitivity of 96.00%, specificity of 84.00%, accuracy of 90.00% and Mathew Correlation Coefficient (MCC) of about 0.81. The total count of aliphatic amino acids, Ala (A), Gly (G), Leu (L), Ile (I), Val (V), Met (M) and Pro (P), was found to be higher, i.e., 42.7 in case of aliphatic nitrilases, whereas it was 40.1 in aromatic nitrilases. On the other hand, aromatic amino acids, Tyr (Y), Trp (W), His (H) and Phe (F) number, were found to be higher, i.e., 12.7 in aromatic nitrilases as compared to aliphatic nitrilases which was 10.7. This approach will help in predicting a nitrilase as aromatic or aliphatic nitrilase based on its amino acid sequence. Access to the scripts can be done logging onto GitHub using keyword ‘Nitrilase’ or ‘’.


Aliphatic nitrilase Aromatic nitrilase Amino acid composition Protein composition server (ProCos) 



The authors are thankful to the Department of Biotechnology, New Delhi for the continuous support to the Bioinformatics Centre, Himachal Pradesh University, Summer Hill, Shimla, India.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interests.

Supplementary material

13205_2018_1102_MOESM1_ESM.docx (34 kb)
Supplementary material 1 (DOCX 34 kb)


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  • Nikhil Sharma
    • 1
  • Ruchi Verma
  • Savitri
    • 2
  • Tek Chand Bhalla
    • 2
    Email author
  1. 1.Bioinformatics CentreHimachal Pradesh UniversityShimlaIndia
  2. 2.Department of BiotechnologyHimachal Pradesh UniversityShimlaIndia

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