Wenk, Martina and Jaenicke, Rainer (1999) Calorimetric analysis of the Ca2+-binding beta gamma-crystallin homolog protein S from Myxococcus xanthus: Intrinsic stability and mutual stabilization of domains. JOURNAL OF MOLECULAR BIOLOGY, 293 (1). pp. 117-124. ISSN 0022-2836, 1089-8638
Full text not available from this repository. (Request a copy)Abstract
The beta gamma-crystallin superfamily consists of a class of homologous two-domain proteins with Greek-key fold. Protein S, a Ca2+-binding spore-coat protein from the soil bacterium Myxococcus xanthus exhibits a high degree of sequential and structural homology with gamma B-crystallin from the vertebrate eye lens. In contrast to gamma B-crystallin, which undergoes irreversible aggregation upon thermal unfolding, protein S folds reversibly and may therefore serve as a model in the investigation of the thermodynamic stability of the eye-lens crystallins. The thermal denaturation of recombinant protein S (PS) and its isolated domains was studied by differential scanning calorimetry in the absence and in the presence of Ca2+ at varying pH. Ca2+-binding leads to a stabilization of PS and its domains and increases the cooperativity of their equilibrium unfolding transitions. The isolated N-terminal and C-terminal domains (NPS and CPS) obey the two-state model, independent of the pH and Ca2+-binding; in the case of PS, under all conditions, an equilibrium intermediate is populated. The first transition of PS may be assigned to the denaturation of the C-terminal domain and the loss of domain interactions, whereas the second one coincides with the denaturation of the isolated N-terminal domain. At pH 7.0, in the presence of Ca2+, where PS exhibits maximal stability, the domain interactions at 20 degrees C contribute 20 kJ/mol to the overall stability of the intact protein. (C) 1999 Academic Press.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | SPORE COAT PROTEIN; DIFFERENTIAL SCANNING CALORIMETRY; X-RAY-ANALYSIS; CALF EYE LENS; NONLENS MEMBER; HEAT-CAPACITY; II-CRYSTALLIN; B-CRYSTALLIN; SUPERFAMILY; VERTEBRATE; differential scanning calorimetry; beta gamma-crystallin; protein stability; two-domain protein; domain interactions |
| Subjects: | 500 Science > 570 Life sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Biophysik und physikalische Biochemie |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 13 Dec 2022 14:28 |
| Last Modified: | 13 Dec 2022 14:28 |
| URI: | https://pred.uni-regensburg.de/id/eprint/48924 |
Actions (login required)
 |
View Item |
