Conformational destabilization of Bacillus licheniformis α-amylase induced by lysine modification and calcium depletion
Bacillus licheniformis α-amylase (BLA) was chemically modified using 100-fold molar excess of succinic anhydride over protein or 0.66 M potassium cyanate to obtain 42 % succinylated and 81 % carbamylated BLAs. Size and charge homogeneity of modified preparations was established by Sephacryl S-200 HR...
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| Format: | Article |
| Language: | English |
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Polish Biochemical Society
2011
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| Online Access: | http://psasir.upm.edu.my/id/eprint/22322/ http://psasir.upm.edu.my/id/eprint/22322/1/Conformational%20destabilization%20of%20Bacillus%20licheniformis%20%CE%B1.pdf |
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| author | Tan, Cheau Yuaan Raja Abdul Rahman, Raja Noor Zaliha Abdul Kadir, Habsah Tayyab, Saad |
| author_facet | Tan, Cheau Yuaan Raja Abdul Rahman, Raja Noor Zaliha Abdul Kadir, Habsah Tayyab, Saad |
| author_sort | Tan, Cheau Yuaan |
| building | UPM Institutional Repository |
| collection | Online Access |
| description | Bacillus licheniformis α-amylase (BLA) was chemically modified using 100-fold molar excess of succinic anhydride over protein or 0.66 M potassium cyanate to obtain 42 % succinylated and 81 % carbamylated BLAs. Size and charge homogeneity of modified preparations was established by Sephacryl S-200 HR gel chromatography and polyacrylamide gel electrophoresis. Conformational alteration in these preparations was evident by the larger Stokes radii (3.40 nm for carbamylated and 3.34 nm for succinylated BLAs) compared to 2.43 nm obtained for native BLA. Urea denaturation results using mean residue ellipticity (MRE) as a probe also showed conformational destabilization based on the early start of transition as well as ΔGDH2O values obtained for both modified derivatives and Ca-depleted BLA. Decrease in ΔGDH2O value from 5,930 cal/mol (for native BLA) to 3,957 cal/mol (for succinylated BLA), 3,336 cal/mol (for carbamylated BLA) and 3,430 cal/mol for Ca-depleted BLA suggested reduced conformational stability upon modification of amino groups of BLA or depletion of calcium. Since both succinylation and carbamylation reactions abolish the positive charge on amino groups (both α- and ε- amino), the decrease in conformational stability can be ascribed to the disruption of salt bridges present in the protein which might have released the intrinsic calcium from its binding site. |
| first_indexed | 2025-11-15T08:31:11Z |
| format | Article |
| id | upm-22322 |
| institution | Universiti Putra Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-15T08:31:11Z |
| publishDate | 2011 |
| publisher | Polish Biochemical Society |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | upm-223222016-01-12T03:05:34Z http://psasir.upm.edu.my/id/eprint/22322/ Conformational destabilization of Bacillus licheniformis α-amylase induced by lysine modification and calcium depletion Tan, Cheau Yuaan Raja Abdul Rahman, Raja Noor Zaliha Abdul Kadir, Habsah Tayyab, Saad Bacillus licheniformis α-amylase (BLA) was chemically modified using 100-fold molar excess of succinic anhydride over protein or 0.66 M potassium cyanate to obtain 42 % succinylated and 81 % carbamylated BLAs. Size and charge homogeneity of modified preparations was established by Sephacryl S-200 HR gel chromatography and polyacrylamide gel electrophoresis. Conformational alteration in these preparations was evident by the larger Stokes radii (3.40 nm for carbamylated and 3.34 nm for succinylated BLAs) compared to 2.43 nm obtained for native BLA. Urea denaturation results using mean residue ellipticity (MRE) as a probe also showed conformational destabilization based on the early start of transition as well as ΔGDH2O values obtained for both modified derivatives and Ca-depleted BLA. Decrease in ΔGDH2O value from 5,930 cal/mol (for native BLA) to 3,957 cal/mol (for succinylated BLA), 3,336 cal/mol (for carbamylated BLA) and 3,430 cal/mol for Ca-depleted BLA suggested reduced conformational stability upon modification of amino groups of BLA or depletion of calcium. Since both succinylation and carbamylation reactions abolish the positive charge on amino groups (both α- and ε- amino), the decrease in conformational stability can be ascribed to the disruption of salt bridges present in the protein which might have released the intrinsic calcium from its binding site. Polish Biochemical Society 2011 Article PeerReviewed application/pdf en http://psasir.upm.edu.my/id/eprint/22322/1/Conformational%20destabilization%20of%20Bacillus%20licheniformis%20%CE%B1.pdf Tan, Cheau Yuaan and Raja Abdul Rahman, Raja Noor Zaliha and Abdul Kadir, Habsah and Tayyab, Saad (2011) Conformational destabilization of Bacillus licheniformis α-amylase induced by lysine modification and calcium depletion. Acta Biochimica Polonica, 58 (3). pp. 405-412. ISSN 0001-527X; ESSN: 1734-154X http://www.actabp.pl/#File?./html/3_2011/405.html |
| spellingShingle | Tan, Cheau Yuaan Raja Abdul Rahman, Raja Noor Zaliha Abdul Kadir, Habsah Tayyab, Saad Conformational destabilization of Bacillus licheniformis α-amylase induced by lysine modification and calcium depletion |
| title | Conformational destabilization of Bacillus licheniformis α-amylase induced by lysine modification and calcium depletion |
| title_full | Conformational destabilization of Bacillus licheniformis α-amylase induced by lysine modification and calcium depletion |
| title_fullStr | Conformational destabilization of Bacillus licheniformis α-amylase induced by lysine modification and calcium depletion |
| title_full_unstemmed | Conformational destabilization of Bacillus licheniformis α-amylase induced by lysine modification and calcium depletion |
| title_short | Conformational destabilization of Bacillus licheniformis α-amylase induced by lysine modification and calcium depletion |
| title_sort | conformational destabilization of bacillus licheniformis α-amylase induced by lysine modification and calcium depletion |
| url | http://psasir.upm.edu.my/id/eprint/22322/ http://psasir.upm.edu.my/id/eprint/22322/ http://psasir.upm.edu.my/id/eprint/22322/1/Conformational%20destabilization%20of%20Bacillus%20licheniformis%20%CE%B1.pdf |