Nidhee Chaudhary
Amity Institute of Biotechnology, Amity University, Sector-125, Noida-201303, Uttar Pradesh, India.

ABSTRACT

In the present investigation amino acid sequence analysis of thermostable endo-ß-1, 4-glucanase purified from Trichoderma viride is being reported. The purified enzyme was found to be thermostable up to 50 0C for prolonged 48 h and showed a novel N-terminal 15 amino acid sequence to be ‘SYPNKQPYGPSGFWM’ entered in the UniProt knowledgebase under the accession number P85218. However, T. viride endo- ß-1, 4-glucanase like all microbial cellulase appears to have a conserved ‘SG’ amino acid sequence at an identical position in the N-terminal domaine. The computational analysis of N-terminal sequence of the protein used in this study showed that it is unstable. The N-terminal sequence also showed potential cleavage sites by different proteases which may contribute to its instability. The secondary structure analysis showed that the N-terminal sequence has 40% of the 15 a. a. sequence in extended strand and 60% in random coil conformation. Two tyrosine phosphorylation sites were predicted in the N-terminal sequence. The N-terminal sequence was also examined for the presence of kinase specific phosphorylation sites. The results showed the presence of one potential site which may be phosphorylated by PKC at position 1 of the N-terminal sequence. The analysis for the prediction of the presence of OGlcNAc sites revealed that two such sites may potentially be present in the sequence. We have also predicted the ligand binding site in the N-terminal sequence of the protein. High thermostability of the endo-ß-1, 4-glucanase reflects the potential commercial significance of the enzyme.   Read More …