Folding of an Abridged -Lactamase
详细信息 查看全文
- 作者：Javier Santos ; Leopoldo G. Gebhard ; Valeria A. Risso ; Raul G. Ferreyra ; Juan P. F. C. Rossi ; and Mario R. Ermá ; cora
- 刊名：Biochemistry
- 出版年：2004
- 出版时间：February 17, 2004
- 年：2004
- 卷：43
- 期：6
- 页码：1715 - 1723
- 全文大小：174K
- 年卷期：v.43,no.6(February 17, 2004)
- ISSN：1520-4995
文摘
The effects of C-terminal truncation on the equilibrium folding transitions and folding kineticsof B. licheniformis exo small 
fchars/beta2.gif" BORDER=0 ALIGN="middle">-lactamase (ES-fchars/beta2.gif" BORDER=0 ALIGN="middle">L) have been measured. ES-fchars/beta2.gif" BORDER=0 ALIGN="middle">L lacking 19 residues (ES-fchars/beta2.gif" BORDER=0 ALIGN="middle">LCfchars/Delta.gif" BORDER=0 >19) has no enzymic activity. Deletion of the last 14 residues produces ES-fchars/beta2.gif" BORDER=0 ALIGN="middle">LCfchars/Delta.gif" BORDER=0 >14, which is 0.1%active. The enzyme lacking nine residues (ES-fchars/beta2.gif" BORDER=0 ALIGN="middle">LCfchars/Delta.gif" BORDER=0 >9) is nearly fully active, has native optical andhydrodynamic properties, and is protease resistant, a distinguishing feature of the wild-type enzyme.Although ES-fchars/beta2.gif" BORDER=0 ALIGN="middle">LCfchars/Delta.gif" BORDER=0 >9 folds properly, it does so 4 orders of magnitude slower than ES-fchars/beta2.gif" BORDER=0 ALIGN="middle">L, making possiblethe isolation and characterization of a compact intermediate state (IP ES-fchars/beta2.gif" BORDER=0 ALIGN="middle">LCfchars/Delta.gif" BORDER=0 >9). Based on the analysis offolding rates and equilibrium constants, we propose that equilibrium between IP ES-fchars/beta2.gif" BORDER=0 ALIGN="middle">LCfchars/Delta.gif" BORDER=0 >9 and otherintermediate slow folding. Residues removed in ES-fchars/beta2.gif" BORDER=0 ALIGN="middle">LCfchars/Delta.gif" BORDER=0 >9 and ES-fchars/beta2.gif" BORDER=0 ALIGN="middle">LCfchars/Delta.gif" BORDER=0 >14 are helical and firmly integratedinto the enzyme body through many van der Waals interactions involving residues distant in sequence.The results suggest that the deleted residues play a key role in the folding process and also the existenceof a modular organization of the protein matrix, at the subdomain level. The results are compared withother examples of this kind in the folding literature.
fchars/beta2.gif" BORDER=0 ALIGN="middle">-lactamase (ES-fchars/beta2.gif" BORDER=0 ALIGN="middle">L) have been measured. ES-fchars/beta2.gif" BORDER=0 ALIGN="middle">L lacking 19 residues (ES-fchars/beta2.gif" BORDER=0 ALIGN="middle">LCfchars/Delta.gif" BORDER=0 >19) has no enzymic activity. Deletion of the last 14 residues produces ES-fchars/beta2.gif" BORDER=0 ALIGN="middle">LCfchars/Delta.gif" BORDER=0 >14, which is 0.1%active. The enzyme lacking nine residues (ES-fchars/beta2.gif" BORDER=0 ALIGN="middle">LCfchars/Delta.gif" BORDER=0 >9) is nearly fully active, has native optical andhydrodynamic properties, and is protease resistant, a distinguishing feature of the wild-type enzyme.Although ES-fchars/beta2.gif" BORDER=0 ALIGN="middle">LCfchars/Delta.gif" BORDER=0 >9 folds properly, it does so 4 orders of magnitude slower than ES-fchars/beta2.gif" BORDER=0 ALIGN="middle">L, making possiblethe isolation and characterization of a compact intermediate state (IP ES-fchars/beta2.gif" BORDER=0 ALIGN="middle">LCfchars/Delta.gif" BORDER=0 >9). Based on the analysis offolding rates and equilibrium constants, we propose that equilibrium between IP ES-fchars/beta2.gif" BORDER=0 ALIGN="middle">LCfchars/Delta.gif" BORDER=0 >9 and otherintermediate slow folding. Residues removed in ES-fchars/beta2.gif" BORDER=0 ALIGN="middle">LCfchars/Delta.gif" BORDER=0 >9 and ES-fchars/beta2.gif" BORDER=0 ALIGN="middle">LCfchars/Delta.gif" BORDER=0 >14 are helical and firmly integratedinto the enzyme body through many van der Waals interactions involving residues distant in sequence.The results suggest that the deleted residues play a key role in the folding process and also the existenceof a modular organization of the protein matrix, at the subdomain level. The results are compared withother examples of this kind in the folding literature.