Calorimetric studies on solid α-chymotrypsin preparations in air and in organic solvents
Öste-Triantafyllou, Angeliki ; Wehtje, Ernst LU ; Adlercreutz, Patrick LU
and Mattiasson, Bo
LU
(1996)
In BBA - Protein Structure and Molecular Enzymology
1295(1).
p.110-118
- Abstract
Differential scanning calorimetry was the method to investigate the thermostability of chymotrypsin. The transition temperature decreased by approx. 30°C when the dry enzyme became highly hydrated. High degree of hydration corresponded to extensive conformational changes during protein denaturation, reflected by large enthalpy values. Sorbitol, lyophilized together with the enzyme, caused the destabilization of the complex within the whole range of water activities. When the enzyme was equilibrated through the apolar solvent, isooctane, stabilization of chymotrypsin was observed at high water activities, compared to equilibration in air. The presence of isooctane resulted in a remarkable stabilization of the chymotrypsin-sorbitol... (More)
Differential scanning calorimetry was the method to investigate the thermostability of chymotrypsin. The transition temperature decreased by approx. 30°C when the dry enzyme became highly hydrated. High degree of hydration corresponded to extensive conformational changes during protein denaturation, reflected by large enthalpy values. Sorbitol, lyophilized together with the enzyme, caused the destabilization of the complex within the whole range of water activities. When the enzyme was equilibrated through the apolar solvent, isooctane, stabilization of chymotrypsin was observed at high water activities, compared to equilibration in air. The presence of isooctane resulted in a remarkable stabilization of the chymotrypsin-sorbitol complex. A sorbitol concentration of 5 mmol/g of protein was prerequisite to induce stabilization when equilibrated through isooctane at high water activities. The transition enthalpy increased with increasing amounts of sorbitol. Different hydration isotherms were obtained for the air-equilibrated and solvent-equilibrated enzyme preparations. Increasing amounts of buffer salts within the chymotrypsin preparation caused the enhancement of both the temperature and the enthalpy of the transition at a water activity 0.97. Variations on the hydration of the preparations both offered the explanation to the thermal stability results and supported the evidence obtained from enzyme activity studies. Generally, the catalyst whose hydration was suppressed due to its environment exhibited low enzymatic activity.
(Less)
- author
- Öste-Triantafyllou, Angeliki
; Wehtje, Ernst
LU
; Adlercreutz, Patrick
LU
and Mattiasson, Bo
LU
- organization
- publishing date
- 1996-06-07
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Differential scanning calorimetry, Ionic strength, Organic solvent, Sorbitol, Thermostability, Water activity
- in
- BBA - Protein Structure and Molecular Enzymology
- volume
- 1295
- issue
- 1
- pages
- 9 pages
- publisher
- Elsevier
- external identifiers
-
- pmid:8679668
- scopus:0030573525
- ISSN
- 0167-4838
- DOI
- 10.1016/0167-4838(96)00036-2
- language
- English
- LU publication?
- yes
- id
- 708fdfc0-3064-4bc1-a941-0c5032404c5e
- date added to LUP
- 2019-06-22 08:59:35
- date last changed
- 2024-01-01 12:12:34
@article{708fdfc0-3064-4bc1-a941-0c5032404c5e,
abstract = {{<p>Differential scanning calorimetry was the method to investigate the thermostability of chymotrypsin. The transition temperature decreased by approx. 30°C when the dry enzyme became highly hydrated. High degree of hydration corresponded to extensive conformational changes during protein denaturation, reflected by large enthalpy values. Sorbitol, lyophilized together with the enzyme, caused the destabilization of the complex within the whole range of water activities. When the enzyme was equilibrated through the apolar solvent, isooctane, stabilization of chymotrypsin was observed at high water activities, compared to equilibration in air. The presence of isooctane resulted in a remarkable stabilization of the chymotrypsin-sorbitol complex. A sorbitol concentration of 5 mmol/g of protein was prerequisite to induce stabilization when equilibrated through isooctane at high water activities. The transition enthalpy increased with increasing amounts of sorbitol. Different hydration isotherms were obtained for the air-equilibrated and solvent-equilibrated enzyme preparations. Increasing amounts of buffer salts within the chymotrypsin preparation caused the enhancement of both the temperature and the enthalpy of the transition at a water activity 0.97. Variations on the hydration of the preparations both offered the explanation to the thermal stability results and supported the evidence obtained from enzyme activity studies. Generally, the catalyst whose hydration was suppressed due to its environment exhibited low enzymatic activity.</p>}},
author = {{Öste-Triantafyllou, Angeliki and Wehtje, Ernst and Adlercreutz, Patrick and Mattiasson, Bo}},
issn = {{0167-4838}},
keywords = {{Differential scanning calorimetry; Ionic strength; Organic solvent; Sorbitol; Thermostability; Water activity}},
language = {{eng}},
month = {{06}},
number = {{1}},
pages = {{110--118}},
publisher = {{Elsevier}},
series = {{BBA - Protein Structure and Molecular Enzymology}},
title = {{Calorimetric studies on solid α-chymotrypsin preparations in air and in organic solvents}},
url = {{http://dx.doi.org/10.1016/0167-4838(96)00036-2}},
doi = {{10.1016/0167-4838(96)00036-2}},
volume = {{1295}},
year = {{1996}},
}