8—THE MOLECULAR WEIGHTS OF THE LOW-SULPHUR PROTEINS FROM WOOL: A REVIEW

Abstract

Molecular-weight measurements made on solutions of wool proteins that were not separated into high- and low-sulphur fractions are first reviewed. All the published studies of the molecular weights of the low-sulphur group of wool proteins are then critically discussed, in chronological order, from the standpoint of present knowledge. The relationships between the various protein fractions resulting from different methods of extraction arc outlined, and the applicability of the different methods used for measuring their molecular weights and the interpretation of the results obtained with them are considered in some detail, especially with respect to molecular-weight heterogeneity. By such discussion, it is attempted throughout the review to give reasons for thinking which results still have significance towards understanding the rôle of the low-sulphur proteins in the structure of wool and which may now be regarded as of historical interest only. Finally, current knowledge of the molecular weights of the low-sulphur wool proteins is summarized, and aspects of their solution behaviour that still need investigation are indicated.

KEY WORDS (SPECIFIC TERMS):

• REVIEWS
• NUMBER-AVERAGE MOLECULAR WEIGHT
• WEIGHT-AVERAGE MOLECULAR WEIGHT
• PH
• SEDIMENTATION COEFEICIENT
• SEDIMENTATION EQUILIBRIUM
• OSMOTIC PRESSURE
• MOVING-BOUNDARY ELECTROPHORESIS
• STARCH-GEL ELECTROPHORESIS
• ACRYLAMIDE-GEL ELECTROPHORESIS
• PEPTIDE-BOND HYDROLYSIS
• GEL FILTRATION
• CENTRIFUGAL FRACTIONATION
• PRECIPITATION
• LIGHT-SCATTERING
• FRONTAL ANALYSIS
• ARCHIBALD METHOD
• MENISCUS-DEPLETION METHOD
• WOOL
• LOW-SULPHUR PROTEINS
• HIGH-SULPHUR PROTEINS
• KERATIN
• KERATEINE
• KERATOSE
• S-CARBOXYMETHYL KERATEINE
• HIGH-GLYCINE–TYROSINE PROTEINS
• COMPONENT 7
• COMPONENT 8
• UREA
• DISULPHIDE BONDS
• PEPTIDE BONDS
• SURFACE BALANCE
• ULTRACENTRIFUGES

KEY WORDS (BROADER TERMS):

• MOLECULAR WEIGHT
• ELECTROPHORESIS
• HYDROLYSIS
• CHEMICAL REACTIONS
• FRACTIONATION
• PROTEINS
• CHEMICAL BONDS