Proteins on the edge of extreme : from chaperonin-assisted to ultrafast protein folding and origins of protein hyperthermostability / Mark D. Shtilerman.

Format:

Book

Manuscript

Microformat

Thesis/Dissertation

Author/Creator:

Shtilerman, Mark D.

Contributor:

Englander, S. Walter, advisor.

University of Pennsylvania.

Language:

English

Subjects (All):

Penn dissertations--Biochemistry.

Biochemistry--Penn dissertations.

Penn dissertations--Molecular biophysics.

Molecular biophysics--Penn dissertations.

Biochemistry and Molecular Biophysics.

Academic Dissertations as Topic.

Medical Subjects:

Biochemistry and Molecular Biophysics.

Academic Dissertations as Topic.

Local Subjects:

Penn dissertations--Biochemistry.

Biochemistry--Penn dissertations.

Penn dissertations--Molecular biophysics.

Molecular biophysics--Penn dissertations.

Physical Description:

xii, 104 pages : illustrations (some color) ; 29 cm

Production:

1999.

Summary:

This dissertation researches three extremes in protein thermodynamics and kinetics. They are related to each other and related to one of the major questions in protein biochemistry---the question of protein folding.

The extremely fast events in protein folding are often ascribed to the formation of a specific intermediate, but our results demonstrate that they originate in a non-specific contraction of the polypeptide chain to the new solvent conditions. The missing amplitude in fluorescence and circular dichroism stopped-flow experiments reflects polypeptide chain contraction upon dilution from a "good" into a "poor" solvent. No specific folding intermediate can be assigned to this process.

A number of proteins fold extremely slowly and require accessory proteins (e.g., GroEL). It was demonstrated that GroEL assists protein folding by active forceful unfolding of misfolded polypeptides. This reaction requires the complete chaperonin system including nucleotides and proceeds on a biologically relevant time scale (13 sec). The substrate protein is released at the end of each cycle whether it is folded to the native state or not.

After a protein has reached its native state, functional activity and resistance to proteolysis depends to a large extent on its stability. Extremely stable proteins were investigated under stable conditions by hydrogen-exchange NMR. This method provided capabilities needed to simultaneously determine structural aspects and the macroscopic thermodynamic parameters of hyperthermophiles.

Notes:

Supervisor: S. Walter Englander.

Thesis (Ph.D. in Biochemistry and Molecular biophysics) -- University of Pennsylvania, 1999.

Includes bibliographical references.

Local Notes:

University Microfilms order no.: 99-37782.

OCLC:

187477039