Studies on Reduced Wool VIII. N-Acetyl Peptides Isolated From A Major Component

Abstract

Two amino terminal acetyl peptides, N�acetyl Ser.Phe.Asp.Phe (A) and N�acetyl Ser.Tyr.Asp.Phe (B), have been isolated from component 8, one of the two major components present in extracts of reduced and carboxymethylated wool. These peptides could not be eluted from columns of Dowex 1 but could be satis� factorily fractionated by DEAE-cellulose chromatography with a gradient of formic acid and by paper ionophoresis. The yield of peptide A was approximately twice that of peptide B. If the molecular weight of component 8 is 45,000 then these acetyl peptide sequences account for only approximately half of the theoretical amount of terminal peptides. This low recovery and the presence of two different but related terminal peptides provides additional evidence for heterogeneity of component 8, and support the idea .that a family of related proteins is present in keratin.

A second life for low‐grade wool through formation of all‐keratin composites in cystine reducing calcium chloride–water–ethanol solution

“…An alternative procedure to dissolve keratin, bases on the use of concentrated 8 mol L ‐1 urea solution at pH values above 7 . In this process thiol‐based reducing agents such as mercaptoethanol or l ‐cystein are required to open the disulphide bonds and to achieve solubility of the keratin.…”

“…A keratin solvent has to open the hydrogen bonding and the ionic bonding present between adjacent protein chains forming the α‐keratin structure of wool . In addition reductive cleavage of disulphide bridges through action of suited reducing agents is a condition to achieve dissolution . Representative examples for reducing agents are thioglycolate, mercaptoethanol and sulphites …”

“…11 In addition reductive cleavage of disulphide bridges through action of suited reducing agents is a condition to achieve dissolution. 12 Representative examples for reducing agents are thioglycolate, mercaptoethanol and sulphites. [13][14][15] In aqueous media dissolution of wool can be achieved at pH 12 in the presence of thioglycolate as reducing agent, precipitation of a regenerate can be initiated by addition of acetic acid.…”

Some properties of keratin biomaterials: Kerateines

“…Using the method of O'Donnell and Thompson for the production of kerateines [14], and the method of Thompson and O'Donnell for the production of keratoses [31]. Ito et al generated samples from sheep wool and determined isoelectric point, amino acid composition, and biological responses to keratin-coated materials implanted into animal models, also in 1982 [32].…”

“…Methods for oxidation [9][10][11] and reduction [12][13][14] have been in the published literature for more than 100 years and have been summarized in several reviews, most notably by Crewther et al in 1965 [8]. Investigations of the structure and properties of soluble keratins has continued, but beginning in the 1970's, the processing of these protein solutions into derivative physical states such as gels and films began appearing in the literature [15][16][17].…”