Some Effects of Sulphur-Containing Amino Acids on the Growth and Composition of Wool

Reis, PJ; Schinckel, PG

doi:10.1071/bi9630218

Cited by 140 publications

(35 citation statements)

References 15 publications

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“…One of the intriguing features of the UHS keratin proteins in sheep is that their level seems to be sensitive to the supply of cysteine. When the supply of cysteine is increased to the wool follicle by infusion of the sheep per abomasum with this amino acid there is a dramatic increase in the UHS keratin proteins (Reis and Schinckel, 1963;Gillespie and Reis, 1966;Broad et al, 1970). In general the synthesis of the other major components of wool does not vary, although a downregulation of the wool high-glycine/tyrosine keratin proteins has been reported (Gillespie, 1983).…”

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confidence: 99%

Structure and expression of genes for a class of cysteine-rich proteins of the cuticle layers of differentiating wool and hair follicles.

MacKinnon

Powell

Rogers

1990

The Journal of Cell Biology

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Abstract. The major histological components of the hair follicle are the hair cortex and cuticle. The hair cuticle cells encase and protect the cortex and undergo a different developmental program to that of the cortex. We report the molecular characterization of a set of evolutionarily conserved hair genes which are transcribed in the hair cuticle late in follicle development. Two genes were isolated and characterized, one expressed in the human follicle and one in the sheep follicle. Each gene encodes a small protein of 16 kD, containing >50 cysteine residues, ranging from 31 to 36 mol % cysteine. Their high cysteine content and in vitro expression data identify them as ultra-high-sulfur (UHS) keratin proteins. The predicted proteins are composed almost entirely of cysteine-rich and glycinerich repeats. Genomic blots reveal that the UHS keratin proteins are encoded by related multigene families in both the human and sheep genomes. Tissue in situ hybridization demonstrates that the expression of both genes is localized to the hair fiber cuticle and occurs at a late stage in fiber morphogenesis.

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confidence: 99%

Structure and expression of genes for a class of cysteine-rich proteins of the cuticle layers of differentiating wool and hair follicles.

MacKinnon

Powell

Rogers

1990

The Journal of Cell Biology

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“…This is supported by recent work on the sulfur-enrichment of wool by the abotnasal infusion of sheep with cysteine ( 14,15] which has led to the idea that there is a basic structure for wool consisting of micronbrils plus about 20~ matrix r7, 8]. If more cysteine is available to the follicle than is required for the formation of this basic structure, then it is utilized for the formation of increased amounts of those highsulfur components which fill into groups C and D. This also happens under normal feeding conditions.…”

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confidence: 56%

The Relation Between the Crimp of Wool and its Content of High-Sulfur Protein

Gillespie

1965

Textile Research Journal

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1128to have the effect of re-directing any channeled solvent streams over a broader front.Eleven samples of 5 g each were weighed out for determinations by Soxhlet traction with ether for 4 hr and a f urther 44 sampl of 2 g each for the modified column-and-tray method. The results obtained are listed in Table I. There is somewhat more spread in the results obtained by the column-and-tray method than in those from the Soxhlet method, but the results are considered to be sufficiently accurate and reliable for use as a rapid routine control method for determination of residual grease on scoured mohair. , ' Literature Cited 1. Dickinson, Dear Sir:There is still no unanimity on the cause of crimp in wool. The most widely held view is that it results from the unequal contraction of the bilateral segments of the fiber during the final stages of keratinization [2,3,10,12,13]. It has also been suggested [1] that it is a growth phenomenon caused by the rhythmical cycle of muscular contraction. This latter concept has also been used to explain certain aspects of the morphology of . &dquo;doggy wool&dquo; [ 11 ] . ' Snyman [16] made a useful contribution in support of the first theory of crimp formation when, in comparing wool fibers of equal diameter, he found that the greater the crimping rate of a fiber, the greater its content of sulfur and para cortex. The present communication extends this by showing that the increased critvping rate of high-sulfur wools is associated with an increased content of high-sulfur proteins and speci6cally with an increase in those protein components which are richest in sulfur. The low-sulfur proteins on the other hand ap-' pear to be identical in composition.Pairs of Merino wools were selected, such that each member of a pair had about the same diameter but a differing crimping rate. The wools were de-tipped, solvent scoured and solubilized by an extraction with urea-thioglycollate [9]. The soluble proteins, accounting for about 90% of the fiber, were converted to S-carboxymethyl kerateines by reaction with iodoacetate and fractionated into high and low-sulfur fractions by precipitation of the latter at pH 4.4. [5]. The results shown in Table I indicate that the high crimping wools contain the most high-sulfur protein.High-sulfur protein from each wool was run electrophoretically at pH 4.4 in acetic acid-sodium acetate buffer of ionic strength 0.1 and it was found (Fig. 1) that each pair of proteins contained the same sort of components but in differing amounts. The proportion of these components was determined by measuring the rela-tive areas under each region of the electrophoretic patterns of Fig 1. By combining this data with the relevant data in .column 4 of Table I, the amount (g/100g) in wool of each of these components was computed (Table I ). It is apparent that both low and high crimping 1 7

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“…The method of administering supplements of S-amino acids per abomasum (4th stomach of sheep) to increase the sulfur content of wool is described by Reis and Schinckel [12]. The experiment with the sheep used to produce the materials discussed here is described by Reis [13].…”

Section: Methodsmentioning

confidence: 99%

The Torsional Properties of Normal and Sulfur-Enriched Wool Fibers

Armstrong

Feughelman

1969

Textile Research Journal

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The mechanical properties in torsion of single wool fibers of biologically produced high-and low-sulfur content have been studied to determine the effects on torsional behavior. The modulus of rigidity and the torsional relaxation, i.e., the decay in torque with time at a constant degree of twist, were determined in fibers tested in glycerol ("-'0% RH), distilled water, and aqueous solutions of HCl at pH 0.8, 1.8, and 2.9. The sulfur content had no significant effect on the modulus of ridigidy or on the magnitude of the torsional relaxation of dry fibers. Again, for fibers tested in distilled water, no significant effect of sulfur content on the modulus of rigidity was observed, but the percent decay in torque was measurably affected. The decay in torque in 1 hr for fibers of normal wool amounted to 23% of the initial torque and that for fibers of sulfur-enriched wool amounted to 15%. This difference in torsional relaxation behavior of wet fibers of the two wools was not thought to be due to the difference in sulfur content but may partly be linked with the aspartic acid content of the two wools. The modulus of rigidity and the torsional relaxation of fibers in aqueous H CI decreased with decreasing pH to as little as one third of the values obtained in distilled water, presumably due to the breaking of salt links, the decrease being greater for the sulfur-enriched wools.

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Some Effects of Sulphur-Containing Amino Acids on the Growth and Composition of Wool

Abstract: The effect on wool growth and the sulphur content of wool of supplements of L-oyswine, DL-methionine, and casein, given per abomasum a�s a continuous infusion, has been examined.

Cited by 140 publications

References 15 publications

Structure and expression of genes for a class of cysteine-rich proteins of the cuticle layers of differentiating wool and hair follicles.

Structure and expression of genes for a class of cysteine-rich proteins of the cuticle layers of differentiating wool and hair follicles.

The Relation Between the Crimp of Wool and its Content of High-Sulfur Protein

The Torsional Properties of Normal and Sulfur-Enriched Wool Fibers

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