Metal-dependent thermal stability of recombinant endo-mannanase (ManB-1601) belonging to family GH 26 from Bacillus sp. CFR1601

Praveen Kumar, Srivastava and Appu Rao, G. and Mukesh, Kapoor (2016) Metal-dependent thermal stability of recombinant endo-mannanase (ManB-1601) belonging to family GH 26 from Bacillus sp. CFR1601. Enzyme and Microbial Technology, 84. pp. 41-49.

PDF 1-s2.0-S0141022915300910-main.pdf - Published Version Restricted to Registered users only Download (2MB) | Request a copy

Abstract

A GH 26 endo-mannanase from Bacillus sp. CFR1601 was purified to homogeneity (Mw ∼39 kDa, specific activity 10,461.5 ± 100 IU/mg). Endo-mannanase gene (manb-1601, 1083 bp, accession No. KM404299) was expressed in Escherichia coli BL21 (DE3) and showed typical fingerprints of ␣/␤ proteins in the far-UV CD. A high degree of conservation among amino acid residues involved in metal chelation (His- 1, 23 and Glu-336) and internal repeats (122–152 and 181–212) was observed in endo-mannanases reported from various Bacillus sp. Thermal inactivation kinetics suggested that metal ions are quintessen- tial for stabilization of ManB-1601 structure as holoenzyme (Ea 87.4 kcal/mol, �H 86.7 kcal/mol, �S 186.6 cal/k/mol) displayed better values of thermodynamic parameters compared to metal-depleted ManB-1601 (Ea 47 kcal/mol, �H 45.7 kcal/mol, �S 64.7 cal/k/mol). EDTA treatment of ManB-1601 not only lead to transitions in both secondary and tertiary structure but also promulgated the population of conformational state that unfolds at lower temperature. ManB-1601 followed a three-state process for thermal inactivation wherein loss of tertiary structure preceded the concurrent loss of secondary structure and activity.

Item Type:	Article
Uncontrolled Keywords:	Endo-mannanase, Bacillus sp. Thermal stability, Metal-binding site, GH family 26
Subjects:	500 Natural Sciences and Mathematics > 07 Life Sciences > 04 Microbiology > 02 Bacteriology 600 Technology > 08 Food technology > 16 Nutritive value > 05 Enzymes
Divisions:	Protein Chemistry and Technology
Depositing User:	Somashekar K S
Date Deposited:	10 Mar 2025 08:57
Last Modified:	10 Mar 2025 08:57
URI:	http://ir.cftri.res.in/id/eprint/19246

Actions (login required)

View Item