Wilfred H. Ward

The Molecular Size of Proteins from Several Wools Solubilized in Aqueous Urea

The soluble proteins isolated from normal wools differing widely in geographical origin, fineness, and breed show the same behavior in ultracentrifugation and diffusion. The wool protein, made soluble in aqueous 10M urea by reduction, has a sedimentation constant ap proaching 1.2 S at zero protein concentration, referred to water at 20°C. In the presence of 0.2N lithium chloride the limiting sedimentation constant is 1.6S. The sedimentation con .stant increases with decreasing concentration of either protein or urea. Similar values are found in other media. The diffusion constant of 2% to 3% solutions is 4.9 × 10-7 cm.2 sec.-1, referred to water at 20°C. Corresponding sedimentation and diffusion measurements give the average molecular weight, 14,000, and the unusually high molar frictional ratio, 2.8, suggesting high asymmetry, high solvation, or a combination of these.

Acrylonitrile-Stabilized Wool Keratin Derivatives: Western Regional Research Laboratory1 Albany 10, California March 2, 1959

, , .... , tan’ 9, cos 9, ously referenced article by the factor 2 ~1 cos 9,)~ 2 (1 coo 0.)’ For small angles 9&dquo; the effect is small. Ratios of torques are not changed. This factor should be present in the final expressions for torque, Equations 10, 32, 35, and 36, and those results shown as ordinates on Figures 3, 8, and 9 should be multiplied by it. For convenience, a table of numerical values of the factor is given below for various helix angles.

Fabric Oil Repellency as Related to the Critical Surface Tension and Stiffness of Coating Material

Although a low critical surface tension for wetting ( 15 dynes/cm or less) is necessary for oil repellency, examples of fluoropolymers with low critical surface tensions are cited that are ineffective for making wool textiles oil repellent. In contrast to effective polymers, these have relatively high glass transition temperatures (ahove 25°C) and are therefore more brittle. Scanning electron microscopy of fabrics coated with such ineffective materials supports the idea that such coatings are flawed, fragile, and poorly adherent.

THE AMINO ACID COMPOSITION OF SELECTED PROTEINS AND POLYPEPTIDES

Publisher Summary This chapter discusses the amino acid composition of selected proteins and polypeptides. Compositions are reported in various units, not all redundant but not always necessary. Protein structure and function might be studied in terms of the number of amino acid residues of each different kind per molecule. When the molecular weight is not known, or when one wants to compare analyses as they are obtained in terms of sample weight, moles per unit weight is a natural related unit. Summations of analyses in weight percentages of the various residues and of the nitrogen of each constituent as percentage of total nitrogen are important tests of completeness of analysis.

RECORDING, PLATE-MEASURING SYSTEM FOR THE ULTRACENTRIFUGE.

Abstract We describe a system appropriate for measuring photographs from ultracentrifuge, free diffusion, or electrophoresis experiments recorded with schlieren or interference optics. The main parts are commercially available. Cartesian coordinates of significant features of the photographs are converted to digital form by means of decimal digital encoders attached to the two lead screws of a two-coordinate measuring microscope. The lead screw positions are continuously displayed on lampbank indicators. On command, the readings are automatically typed, punched into paper tape, or both. Identifying information and supplementary data for computation can be inserted as needed in the typed record or also in the tape. When coordinate readings are wanted at predetermined equal intervals, the abscissa ( x ) lead screw is advanced automatically to the successive positions at which measurements of the ordinate ( y ) are wanted. At present, for schlieren records, adjustment of the y lead screw and initial adjustment of the x lead screw are made manually with visual inspection of the projected image. This system increases the rate at which plates can be measured, completely avoids human error in writing down and transcribing measurements, and records measurements in forms convenient for evaluation either by electronic digital computation or by more usual methods.

43—ACRYLONITRILE-STABILIZED WOOL KERATIN DERIVATIVES: II—Development of a Reproducible Preparation from Cortical Cell Residues

Apparently reproducible preparations of molecular weight 30,000 have been obtained from cortical-cell residues (from acid digestion) by treating cold reduced solutions with acrylonitrile under nitrogen. The yield is 15 to 20% of the original wool or 20 to 30% of the isolated cortical-cell residues. This recovered product is lower in sulphur and in amino nitrogen content than either the original wools or the cortical-cell residues. The product of molecular weight 30,000 is provisionally related to the α1-keratose fraction of oxidized wool, or corresponding kerateine fractions, by hydrolytic fission of, on the average, not more than two peptide bonds per chain. The low-molecular-weight, high-sulphur fraction that is lost by dialysis or failure to precipitate is related to the γ-keratose fraction.

The effects of ethylene glycol on wool fibers.

We have previously shown that ethylene glycol can be a useful solvent for certain continuous processes in wool textile finishing. A brief treatment in hot ethylene glycol can (1) impart considerable stretch properties to woven wool fabric when treated in a slack condition (Pittman and Wasley, 1974; Pittman and Wasley, 1975), (2) produce permanent set, i.e. creases or crimp, to wool held in a constrained configuration during treatment (Pittman et al., 1975) and (3) produce rapid and thorough dyeing when used as a dyebath medium (Pittman et al., 1976).

Dissolution and Properties of Reduced Wool in Dilute Acid Near Room Temperature

feathers, and the horny layer of skin, can only be separated by breaking disulfide bonds that cross-link the natural tissues. Polyionic derivatives―keratoses or carboxymethylkerateines-are used for most recent studies of chemical structure and molecular properties of keratin proteins because they are soluble and stable near neutrality. However, the many new ionic groups make these derivatives very_different from the original keratin and its natural precursors. For insight into the properties and formation of keratins, it is desirable also to study unsubstituted reduced derivatives, kerateines, that are more like the natural precursors.