Page 139 - Academic Press Encyclopedia of Physical Science and Technology 3rd BioChemistry

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Encyclopedia of Physical Science and Technology EN013H-614 July 27, 2001 10:29

Protein Folding

Maurice Eftink
Susan Pedigo
University of Mississippi

I. Introduction
II. Stability of the Tertiary Fold
III. Folding Pathways
IV. Empirical Approaches
V. Closing Comments

GLOSSARY this folded structure is achieved remains one of the most
important questions in biochemistry and molecular biol-
Absorbance spectroscopy Monitors conformational ogy. Current efforts toward sequencing the human genome
transitions in macromolecules by measuring absor- and the genomes of other organisms have led to a large
bance changes, usually in the aromatic region of the number of putative protein sequences. Much as the genetic
ultraviolet (UV) spectrum. code is the Rosetta stone that gave the link between DNA
Circular dichroism A very commonly used method for and protein sequences, we now need to find such a link
studying protein conformational changes. between protein sequences and final structure and func-
Fluorescence The most sensitive of the commonly used tion. Without knowledge of the rules of protein folding,
optical methods for studying protein unfolding transi- there can be little understanding of function from protein
tions. sequence information alone.
Nuclear magnetic resonance A powerful method for
studies with proteins, as there is such a large number
of resolved signals. I. INTRODUCTION
Scanning calorimetry Measures the variation in the spe-
cific heat of a protein containing solution as a protein We have interest in protein structure and function at both
is thermally unfolded. a fundamental and a practical level. There is astound-
ing beauty in the mastery with which nature has tailored
molecules for specific functions, activity levels, regula-
PROTEINS are only functional as enzymes, transport tory properties, and integration into complex macromolec-
agents, receptors, and so forth when they exist in a folded, ular assemblies. As will be discussed, in most cases,
three-dimensional, native structure. The means by which these molecules assume a final stably folded structure

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