The Amino Acid Composition of Keratins

Simmonds, DH

doi:10.1071/bi9550537

Cited by 27 publications

(18 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Chemical analyses have been made of intact fibres (Simmonds 1954(Simmonds , 1955(Simmonds , 1956Oorfield and Robson 1955;Ward, Binkley, and Snell 1955;Bradbury 1960a) and of separated cuticle (Geiger 1944;Lustig and Kondritzer 1945;Lindley 1947;Elliott and Roberts 1957;Elliott, Asquith, and Rawson 1959;Bradbury 1959Bradbury , 1960a and cortical cells (Ward, Binkley, and Snell 1955 ;Ward and Bartulovich 1956;Simmonds and Bartulovich 1958). However, the results of analyses of separated components obtained by different workers have not shown good agreement for three reasons.…”

Section: Introductionmentioning

confidence: 99%

The Chemical Composition of Wool

Bradbury¹,

Chapman²

1964

Aust. Jnl. Of Bio. Sci.

View full text Add to dashboard Cite

SummaryA study is made of the disruption of wool by ultrasonic disintegration and the separation and identification by microscopy of the major components of the fibre. The ultrasonic disintegration process is investigated empirically in order to establish the conditions under which maximum rates of disruption occur. Of a large number of liquids examined it is found, in confirmation of earlier work, that the rate of disintegration of wool is very slow in water but usually increases in amount as the swelling of the fibre increases. The several exceptions to this rule show that there are other factors of secondary importance in determining the rate of disruption. The amount of disruption is sufficient for preparative purposes and increases in amount in the series dimethyl sulphoxide, formic acid, and dichloroacetic acid.Cortical cells, cuticle, and disrupted cortical cells can be separated on the basis of their different sizes by a combination of screening and sedimentation methods. The histological purity of the fractions is established by light and electron microscopy. It is also shown that the random nature of the ultrasonic disruption process results in the production of components of a continuous range of sizes from cortical cells down to needle· like components of size approaching that of microfibrils.

show abstract

Section: Introductionmentioning

confidence: 99%

The Chemical Composition of Wool

Bradbury¹,

Chapman²

1964

Aust. Jnl. Of Bio. Sci.

View full text Add to dashboard Cite

show abstract

“…Hydrolysis of hair fi bers and analysis of amino acid composition were performed with a modifi cation of previously reported methods [3,4,25,29] . Five hair fi bers of 1 cm in length, which were selected at random from the same regions as the other comparative tresses, were hydrolyzed with 1 ml 6 M HCl in a sealed ampoule at 110 ° C for 24 h. The hydrolysate in the ampoule was dried using a Centrifugal Concentrator CC-105 (Tomy Seiko, Saitama, Japan).…”

Section: Analysis Of Hydrolyzed Amino Acidsmentioning

confidence: 99%

“…They are composed of a central medulla of loosely connected cells surrounded by more tightly packed, spindle-shaped cortical cells, with 5-10 layers of fl at overlapping scale-like cuticle cells, and with a cell membrane complex (CMC) located in intercellular spaces between the cuticle and the cortical cells [1] . Hair proteins are characterized by a richly crosslinked amino acid, cystine (subsequently termed half-cystine, H-CYS) [2][3][4] , which provides hair fi bers with tensile elasticity, and aids their mechanical resistance against elongation, bending and torsion [1,5,6] . Hair lipids are composed of squalene (SQ), wax esters (WE), triglycerides (TG), free fatty acids (FFA), cholesterol (CH), ceramides (CER), cholesterol sulfate (CS) and 18-methyleicosanoic acid (18-MEA) [7][8][9][10][11][12][13][14] .…”

Section: Introductionmentioning

confidence: 99%

Damage to Human Hair Caused by Repeated Bleaching Combined with Daily Weathering during Daily Life Activities

et al. 2004

View full text Add to dashboard Cite

Background: Although it is well known that chemical oxidation with alkaline hydrogen peroxide damages human hair, little is known about the effects of bleaching during daily life activities which may alter hair components. Objective: To determine the effects of bleaching combined with daily weathering on lipids and amino acids in hair. Methods: Levels of lipids and amino acids were analyzed by chromatography in scalp hair fibers collected from three different females and in experimentally treated hair. Results: Bleaching combined with daily weathering induced the loss of 18-methyleicosanoic acid (18-MEA) and the conversion of half-cystine (H-CYS) to cysteic acid (CYS-A), which were the most remarkable changes among all lipids and amino acids tested. Although a single bleaching had no effect, repeated bleaching combined with daily weathering elicited significant decreases in other intrinsic endogenous lipids and alterations in amino acids that are characteristic for the cuticle. Conclusion: Hair damage, eventually leading to the worst damage such as splitting, is caused by bleaching during daily life activities and is mainly attributable to the loss of 18-MEA as well as the conversion of H-CYS to CYS-A.

show abstract

“…Thus, gaps exist between the scales where the intercellular material extends to the exterior fiber surface (approximately 0.05% (Joko et al, 1985)). (Simmonds, 1955).…”

Section: Introductionmentioning

confidence: 99%