Intrinsic halotolerance of the psychrophilic alpha-amylase from Pseudoalteromonas haloplanktis
(2007) In Extremophiles 11(3). p.505-515- Abstract
- The halotolerance of a cold adapted alpha-amylase from the psychrophilic bacterium Pseudoalteromonas haloplanktis (AHA) was investigated. AHA exhibited hydrolytic activity over a broad range of NaCl concentrations (0.01-4.5 M). AHA showed 28% increased activity in 0.5-2.0 M NaCl compared to that in 0.01 M NaCl. In contrast, the corresponding mesophilic (Bacillus amyloliquefaciens) and thermostable (B. licheniformis) alpha-amylases showed a 39 and 46% decrease in activity respectively. Even at 4.5 M NaCl, 80% of the initial activity was detected for AHA, whereas the mesophilic and thermostable enzymes were inactive. Besides an unaltered fluorescence emission and secondary structure, a 10 degrees C positive shift in the temperature optimum,... (More)
- The halotolerance of a cold adapted alpha-amylase from the psychrophilic bacterium Pseudoalteromonas haloplanktis (AHA) was investigated. AHA exhibited hydrolytic activity over a broad range of NaCl concentrations (0.01-4.5 M). AHA showed 28% increased activity in 0.5-2.0 M NaCl compared to that in 0.01 M NaCl. In contrast, the corresponding mesophilic (Bacillus amyloliquefaciens) and thermostable (B. licheniformis) alpha-amylases showed a 39 and 46% decrease in activity respectively. Even at 4.5 M NaCl, 80% of the initial activity was detected for AHA, whereas the mesophilic and thermostable enzymes were inactive. Besides an unaltered fluorescence emission and secondary structure, a 10 degrees C positive shift in the temperature optimum, a stabilization factor of > 5 for thermal inactivation and a Delta T-m of 8.3 degrees C for the secondary structure melting were estimated in 2.7 M NaCl. The higher activation energy, half-life time and T-m indicated reduced conformational dynamics and increased rigidity in the presence of higher NaCl concentrations. A comparison with the sequences of other halophilic alpha-amylases revealed that AHA also contains higher proportion of small hydrophobic residues and acidic residues resulting in a higher negative surface potential. Thus, with some compromise in cold activity, psychrophilic adaptation has also manifested halotolerance to AHA that is comparable to the halophilic enzymes. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/660501
- author
- Srimathi, Soundararajan LU ; Jayaraman, Gurunathan ; Feller, Georges ; Danielsson, Bengt LU and Narayanan, Paranji R.
- organization
- publishing date
- 2007
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- halotolerance, halophilic, acidic protein, Pseudoalteromonas haloplanktis alpha-amylase, psychrophilic, stability
- in
- Extremophiles
- volume
- 11
- issue
- 3
- pages
- 505 - 515
- publisher
- Springer
- external identifiers
-
- wos:000246353300010
- scopus:34248392177
- pmid:17310272
- ISSN
- 1433-4909
- DOI
- 10.1007/s00792-007-0062-5
- language
- English
- LU publication?
- yes
- id
- f998d8cb-73ae-46b1-910f-f58100c25f8e (old id 660501)
- date added to LUP
- 2016-04-01 11:53:12
- date last changed
- 2022-04-28 21:23:08
@article{f998d8cb-73ae-46b1-910f-f58100c25f8e,
abstract = {{The halotolerance of a cold adapted alpha-amylase from the psychrophilic bacterium Pseudoalteromonas haloplanktis (AHA) was investigated. AHA exhibited hydrolytic activity over a broad range of NaCl concentrations (0.01-4.5 M). AHA showed 28% increased activity in 0.5-2.0 M NaCl compared to that in 0.01 M NaCl. In contrast, the corresponding mesophilic (Bacillus amyloliquefaciens) and thermostable (B. licheniformis) alpha-amylases showed a 39 and 46% decrease in activity respectively. Even at 4.5 M NaCl, 80% of the initial activity was detected for AHA, whereas the mesophilic and thermostable enzymes were inactive. Besides an unaltered fluorescence emission and secondary structure, a 10 degrees C positive shift in the temperature optimum, a stabilization factor of > 5 for thermal inactivation and a Delta T-m of 8.3 degrees C for the secondary structure melting were estimated in 2.7 M NaCl. The higher activation energy, half-life time and T-m indicated reduced conformational dynamics and increased rigidity in the presence of higher NaCl concentrations. A comparison with the sequences of other halophilic alpha-amylases revealed that AHA also contains higher proportion of small hydrophobic residues and acidic residues resulting in a higher negative surface potential. Thus, with some compromise in cold activity, psychrophilic adaptation has also manifested halotolerance to AHA that is comparable to the halophilic enzymes.}},
author = {{Srimathi, Soundararajan and Jayaraman, Gurunathan and Feller, Georges and Danielsson, Bengt and Narayanan, Paranji R.}},
issn = {{1433-4909}},
keywords = {{halotolerance; halophilic; acidic protein; Pseudoalteromonas haloplanktis alpha-amylase; psychrophilic; stability}},
language = {{eng}},
number = {{3}},
pages = {{505--515}},
publisher = {{Springer}},
series = {{Extremophiles}},
title = {{Intrinsic halotolerance of the psychrophilic alpha-amylase from Pseudoalteromonas haloplanktis}},
url = {{http://dx.doi.org/10.1007/s00792-007-0062-5}},
doi = {{10.1007/s00792-007-0062-5}},
volume = {{11}},
year = {{2007}},
}