Biopolymers

Biopolymers deals with the methods of physical characterization and the principles underlying them, with emphasis on quantitative aspects of sequence, conformation, and structure in both laboratory-synthesized and native biopolymers. The book reviews structural units of biopolymers and describes characterization of biopolymers, the available techniques, the evaluation of underlying principles, and experimental applications. Some of these methods include Raman spectroscopy, theoretical conformation analysis, electron microscopy, and morphology of laboratory-synthesized polymers. The text explains the factors controlling conformation of polypeptides, the steric maps of dipeptides, potential energy maps, and the calculation of tertiary polypeptide structure. The investigator can use X-ray diffraction to determine the structure of polymers and macromolecules, such as diffraction by a crystal, by poorly crystalline polymer systems, or by a helical chain. The book notes that materials that can be crystallized from strong solvents reveal morphology similar to that of commercial polymers, which are different from that of polypeptides or proteins in native tissue. The text explains the basis of infrared and Raman spectroscopy in probing molecular structure and conformation of biological macromolecules. The investigator can also employ nuclear magnetic resonance and dielectric relaxation for conformation in physical organic chemistry, outside of biological macromolecule applications. The book can prove helpful for researchers in ultra-trace analysis, polymer research, and analytical chemistry.

Preface

1. Structural Units of Biopolymers

Introduction

Amino Acids

Sugars

Nucleotides

References

2. Conformation

Introduction

The Peptide Bond

Factors Controlling Conformation of Polypeptides

Characteristics of Helices

Steric Maps of Dipeptides

Interatomic Interaction Potentials

Potential Energy Maps

Calculation of Tertiary Polypeptide Structure and Summary of Polypeptide

Conformation

Conformational Analysis for Other Biopolymers

References

Appendix

3. Structure Determination by X-Ray Diffraction

Introduction

Diffraction of X Rays by a Crystal. The Reciprocal Lattice

Symmetry of Chain Molecules

Structure Determination

Diffraction by Poorly Crystalline Polymer Systems

Diffraction by a Helical Chain

Identification of the Chain Conformation

Single Crystals of Globular Proteins

References

4. Tertiary Structure and Morphology of Synthetic Biopolymers

Introduction

Types of Molecular Arrangement

The Calculation of Crystal Structures

Observation of Morphology of Synthetic Biopolymers

Discussion of Morphology

Morphology of Synthetic Polysaccharides and Polynucleotides

Summary

Appendix: Electron Diffraction

References

5. Infrared and Raman Spectroscopy

Introduction

Spectroscopy of Polypeptides

Spectroscopy of Polynucleotides

Polysaccharides

References

6. Electronic Spectroscopy

Introduction

The Chromophores

The Peptide Bond

Nucleotides

Line Broadening

Oligomers

Ultraviolet Absorption by Biopolymers

Optical Rotation

Optical Rotatory Dispersion

Circular Dichroism

Nucleosides and Nucleotides

Optical Properties of Polysaccharides

Conformational Transitions of Polysaccharides

Spectra of Complexes

References

7. Physical Properties of Biopolymers in Dilute Solutions

Symbols

Introduction

Determination of Particle Size and Shape

Osmometry

Light Scattering

Small-Angle X-Ray Scattering by Solutions of Macromolecules

Viscometry

Sedimentation

Flow Birefringence

Characterization of Conformation, Structure, and Conformational Transitions in Solution

Appendix: Statistical Ways of Averaging a Distribution of Molecular Weights

References

8. Electrical and Magnetic Field Effects

Introduction

Proton Magnetic Resonance

The Chemical Shift

Spin Coupling

Linewidth

The Charge Distribution and Chemical Shifts of Amino Acids

Nuclear Magnetic Resonance Spectroscopy of Peptide Oligomers

Nuclear Magnetic Resonance Spectroscopy of Polypeptides

Coupling Constants and Conformational Analysis

Application of nmr Spectroscopy to Native Proteins

Nuclear Magnetic Resonance Spectroscopy of Polynucleotides

Dielectric Dispersion by Biopolymers

Dielectric Properties of Biopolymer Solutions

Dielectric Dispersion and Rotatory Diffusion Coefficient

Experimental Information

References

9. Conformation of Polypeptides

Homobiopolymers in the Solid State

Homobiopolymers in Solution

Conformation in Mixed Solvents

Temperature-Induced Transitions

Copolymers

Sequential Polypeptides

References

10. Fibrous Proteins and Biopolymer Models

Introduction

Silk Proteins

Collagen

Elastin

Resilin

The Keratins

The Muscle Proteins

Summary of Fibrous Proteins

References

11. The Polysaccharides

Introduction

Polysaccharide Structures

Cellulose

Chitin

Xylans

Mannans

Amylose

Alginic Acids

A-B-Polysaccharides

Carrageenans

Hyaluronic Acid

References

12. Nucleic Acids and Polynucleotides

Introduction

Double-Helical Conformation

Solid-State Structure

Solution Properties

Transfer RNA

Protein Synthesis and the Genetic Code

References

13. Globular Proteins

X-Ray Diffraction

Prediction of Chain Conformation for Globular Proteins

Myoglobin

Hemoglobin

Lysozyme

Ribonuclease

Chymotrypsin

Papain

Carboxypeptidase A

Other Techniques for Determining the Conformation of Globular Protein

References

Author Index

Subject Index