Amino acid sequences of α-helical segments from <i>S</i>-carboxymethylkerateine-A. Tryptic and chymotryptic peptides from a type-II segment

Hogg, Deborah; Dowling, L.M.; Crewther, W.G.

doi:10.1042/bj1730353

Cited by 8 publications

(15 citation statements)

References 27 publications

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“…The automatic sequenator was used to determine the N-terminal sequence ofthe intact chain, unknown sections of the sequences of tryptic peptides, the N-terminal sequences of large peptides obtained by acid cleavage at aspartic acid residues and the location of amide side chains. Together with the analyses given by Hogg et al (1978), these data establish the complete amino acid sequence.…”

mentioning

confidence: 56%

“…To assign amide side chains and to complete the sequence data on tryptic peptides, 200mg of the type-II helical segment was digested with trypsin and the peptides were fractionated by chromatography on DEAE-cellulose with an (NH4),CO3 gradient at pH 8.5 (Hogg et al, 1978). The pooled fractions were freeze-dried and peptides were isolated by highvoltage electrophoresis on Whatman 3MM paper at pH 6.5 and pH 9.0 (Hogg et al, 1978).…”

Section: Isolation Of Tryptic Peptidesmentioning

confidence: 99%

“…To confirm one portion of the sequence a chymotryptic digest ofsegment ChC'6 prepared as described by Hogg et al (1978) was subjected to high-voltage paper electrophoresis for a short period (3000V; 20min) and the most-cationic peptides comprising four adjacent bands were eluted, analysed and their sequences determined manually.…”

Section: Isolation Ofchymotryptic Peptidesmentioning

confidence: 99%

“…Similar segments (type II) constitute a major part of the a-helical fragments precipitated at pH4.0 from partial chymotryptic digests of S-carboxymethylkerateine-A (Crewther & Dowling, 1971). During storage of the material used for earlier studies (Hogg et al, 1978) the homocitrulline content increased, with a concomitant decrease in lysine content. It was therefore presumed that the blocked N-terminus observed for this fraction was due to carbamyolation of the N-terminal amino group by cyanate present in the urea buffers used in disintegrating the fragments and separating their constituent chain segments (Stark et al, 1960).…”

mentioning

confidence: 95%

“…In the preceding paper, Hogg et al (1978) proposed a partial tentative sequence for a helical segment from the low-sulphur fraction S-carboxymethylkerateine-A from wool. Similar segments (type II) constitute a major part of the a-helical fragments precipitated at pH4.0 from partial chymotryptic digests of S-carboxymethylkerateine-A (Crewther & Dowling, 1971).…”

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confidence: 99%

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Amino acid sequences of α-helical segments from S-carboxymethylkerateine-A. Complete sequence of a type-II segment

Crewther¹,

Inglis²,

McKern³

1978

Biochemical Journal

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1. The helical fragments obtained by partial chymotryptic digestion of S-carboxymethylkeratine-A, the low-sulphur fraction from wool, were fractionated into type-I and type-II helical segments in aqueous urea under conditions limiting carbamoylation. 2. The amino acid sequence of a 109-residue type-II segment was completed by using the sequenator. 3. When the data were incorporated into a helical model of 3.6 residues per turn the hydrophobic residues generated a band aligned at a slight angle to the helical axis. This result is in accord with the postulated coiled-coil structure of the crystalline regions of alpha-keratin.

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mentioning

confidence: 56%

Section: Isolation Of Tryptic Peptidesmentioning

confidence: 99%

Section: Isolation Ofchymotryptic Peptidesmentioning

confidence: 99%

mentioning

confidence: 95%

mentioning

confidence: 99%

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Amino acid sequences of α-helical segments from S-carboxymethylkerateine-A. Complete sequence of a type-II segment

Crewther¹,

Inglis²,

McKern³

1978

Biochemical Journal

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Keratin expression in the human hair follicle

Schweizer

1989

Trends in Human Hair Growth and Alopecia Research

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During the past 20 years there has been an impressive accumulation of scientific literature on the proteins which are involved in the formation and differentiation of the hair. It is clear that these studies cannot be segregated from the previous research on wool fiber proteins. Therefore a short compilation of the knowledge in this area will be presented, especially to take into account methodological aspects and difficulties associated with the biochemical analysis of hair proteins.The first detailed description and analysis of the whole set of native hard alpha-keratins of the human hair -recently published by two different laboratories -has provided new evidence for the already widely accepted realization that these proteins represent a distinct subclass of epithelial cytokeratins which is highly conserved in mammals. They seem to be generally involved in the formation of hardened cornified structures and may therefore be regarded as molecular markers for hair/nail type differentiation.Similar to cytokeratins, the hard alpha-keratins can be divided into two characteristic type I and type II subfamilies, each containing four individual members which are encoded by mRNAs of their own. The unambiguous identification of the whole set of proteins by gel electrophoretic methods requires sophisticated focusing conditions which have also enabled it to be shown that the different proteins undergo an increased phosphorylation during hair maturation. Reassociation studies in which collectively separated and solubilized type I and type II proteins were combined in vitro, revealed their capacity to assemble into 8-10 nm filaments provided, however, the reassociation conditions took into account the high cysteine content of the proteins. The presence of four protein subunits in each of the two subfamilies is indicative of the formation of an equal number of distinct keratin pairs, and preliminary immunohistochemical studies with antibodies recognizing either the basic or the acidic proteins in Western blots suggest that the oppositely charged proteins appear coordinately in the keratogenous zone of the forming hair shaft.These new insights in the field of hard alpha-keratin composition, synthesis and localization raise a variety of new questions. It can be predicted that the strategy for the resolution of these questions will certainly involve recombinant DNA techniques to elucidate both the nucleotide and amino acid sequences of the different hard alpha-keratins and their respective mRNAs or genes. These will provide an arsenal for the generation of highly specific gene probes and antibodies which in turn will be a prerequisite to further unraveling of the complex differentiation pathways of the hair from the hair follicle germinative cells.

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Expression of hair-related keratins in a soft epithelium: Subpopulations of human and mouse dorsal tongue keratinocytes express keratin markers for hair-, skin- and esophageal-types of differentiation

Dhouailly

Manabe

et al. 1989

Experimental Cell Research

125

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Amino acid sequences of α-helical segments from S-carboxymethylkerateine-A. Tryptic and chymotryptic peptides from a type-II segment

Cited by 8 publications

References 27 publications

Amino acid sequences of α-helical segments from S-carboxymethylkerateine-A. Complete sequence of a type-II segment

Amino acid sequences of α-helical segments from S-carboxymethylkerateine-A. Complete sequence of a type-II segment

Keratin expression in the human hair follicle

Expression of hair-related keratins in a soft epithelium: Subpopulations of human and mouse dorsal tongue keratinocytes express keratin markers for hair-, skin- and esophageal-types of differentiation

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