scholarly journals Secondary structure of component 8c-1 of α-keratin. An analysis of the amino acid sequence

1986 ◽  
Vol 236 (3) ◽  
pp. 705-712 ◽  
Author(s):  
L M Dowling ◽  
W G Crewther ◽  
D A Parry
Keyword(s):  
Amino Acid ◽  
Secondary Structure ◽  
Amino Acid Sequence ◽  
Intermediate Filament ◽  
Coiled Coil ◽  
Terminal Region ◽  
Striking Similarity ◽  
Intermediate Filament Proteins ◽  
Coil Structure ◽  
Alpha Keratin

The amino acid sequence of component 8c-1 from alpha-keratin was analysed by using secondary-structure prediction techniques, homology search methods, fast Fourier-transform techniques to detect regularities in the linear disposition of amino acids, interaction counts to assess possible modes of chain aggregation and assessment of hydrophilicity distribution. The analyses show the following. The molecule has two lengths of coiled-coil structure, each about 20 nm long, one from residues 56-202 with a discontinuity from about residue 91 to residue 101, and the other from residues 219-366 with discontinuities from about residue 238 to residue 245 and at about residue 306. The acidic and basic residues in the coiled-coil segment between residues 102 and 202 show a 9,4-residue structural period in their linear disposition, whereas between residues 246 and 366 a period of 9.9 residues is observed in the positioning of ionic residues. Acidic and basic residues are out of phase by 180 degrees. Similar repeats occur in corresponding regions of other intermediate-filament proteins. The overall mean values for the repeats are 9.55 residues in the N-terminal region and 9.85 residues in the C-terminal region. The regions at each end of the protein chain (residues 1-55 and 367-412) are not alpha-helical and contain many potential beta-bends. The regions specified in have a significant degree of homology mainly due to a semi-regular disposition of proline and half-cystine residues on a three-residue grid; this is especially apparent in the C-terminal segment, in which short (Pro-Cys-Xaa)n regions occur. The coiled-coil segments of component 8c-1 bear a striking similarity to corresponding segments of other intermediate-filament proteins as regards sequence homology, structural periodicity of ionic residues and secondary/tertiary-structure predictions. The assessments of the probabilities that these homologies occurred by chance indicate that there are two populations of keratin filament proteins. The non-coiled-coil regions at each end of the chain are less hydrophilic than the coiled-coil regions. Ionic interactions between the heptad regions of components 8c-1 and 7c from the microfibrils of alpha-keratin are optimized when a coiled-coil structure is formed with the heptad regions of the constituent chains both parallel and in register.

scholarly journals The amino acid sequence of component 7c, a type II intermediate-filament protein from wool

1989 ◽  
Vol 261 (3) ◽  
pp. 1015-1022 ◽  
Author(s):  
L G Sparrow ◽  
C P Robinson ◽  
D T W McMahon ◽  
M R Rubira
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Intermediate Filament ◽  
Coiled Coil ◽  
British Library ◽  
Intermediate Filament Protein ◽  
Type I ◽  
Type Ii ◽  
Blocking Group ◽  
Intermediate Filament Proteins

Component 7c is one of the four homologous type II intermediate-filament proteins that, by association with the complementary type I proteins, form the microfibrils or intermediate filaments in wool. Component 7c was isolated as the S-carboxymethyl derivative from Merino wool and its amino acid sequence was determined by manual and automatic sequencing of peptides produced by chemical and enzymic cleavage reactions. It is an N-terminally blocked molecule of 491 residues and Mr (not including the blocking group) of 55,600; the nature of the blocking group has not been determined. The predicted secondary structure shows that component 7c conforms to the now accepted pattern for intermediate-filament proteins in having a central rod-like region of approximately 310 residues of coiled-coil alpha-helix flanked by non-helical N-and C-terminal regions. The central region is divided by three non-coiled-coil linking segments into four helical segments 1A, 1B, 2A and 2B. The N-and C-terminal non-helical segments are 109 and 71 residues respectively and are rich in cysteine. Details of procedures use in determining the sequence of component 7c have been deposited as a Supplementary Publication SUP 50152 (65 pages) at the British Library Document Supply Centre, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1989) 257,5. The information comprises: (1) details of chemical and enzymic methods used for cleavage of component 7c, peptides CN1, CN2 and CN3, and various other peptides, (2) details of the procedures used for the fractionation and purification of peptides from (1), including Figures showing the elution profiles from the chromatographic steps used, (3) details of methods used to determine the C-terminal sequence of peptide CN3, and (4) detailed evidence to justify a number of corrections to the previously published sequence.

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

1978 ◽  
Vol 173 (2) ◽  
pp. 365-371 ◽  
Author(s):  
W G Crewther ◽  
A S Inglis ◽  
N M McKern
Keyword(s):  
Amino Acid ◽  
Coiled Coil ◽  
Complete Sequence ◽  
Amino Acid Sequences ◽  
Helical Axis ◽  
Type I ◽  
Type Ii ◽  
Coil Structure ◽  
Aqueous Urea ◽  
Alpha Keratin

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.

The Histidine and Methionine Sequences of Rabbit Skeletal Tropomyosin

1972 ◽  
Vol 50 (3) ◽  
pp. 312-329 ◽  
Author(s):  
R. S. Hodges ◽  
L. B. Smillie
Keyword(s):  
Amino Acid ◽  
Sequence Analysis ◽  
Amino Acid Sequence ◽  
Coiled Coil ◽  
Sequence Information ◽  
Chain Packing ◽  
Hydrophobic Residues ◽  
Coil Structure ◽  
Methionine Residues ◽  
Polypeptide Chains

Amino acid analyses of tropomyosin have previously shown four histidine and 13–14 methionine residues per mole (70 000 daltons) of tropomyosin. The isolation of two unique histidyl and five unique methionyl sequences is described. The number of unique methionyl peptides will undoubtedly be increased when more extensive sequence information becomes available although the value of 2 for the unique histidine sequences is considered to be a maximal one. These data support the conclusion that the two subunits of tropomyosin are similar in amino acid sequence. Both the acetylated NH2-terminal and COOH-terminal sequences of the protein have been determined in this study. The isolation and sequence analysis of two varieties of peptides arising from the COOH-terminus of the protein indicates either a degree of proteolysis during its isolation or a difference in the constituent polypeptide chains of tropomyosin in this region of their structures. The limited sequences reported indicate a repeat of hydrophobic residues as required by the inter-chain packing of a coiled-coil structure.

scholarly journals Amino-Acid Sequence of Rabbit Skeletal Tropomyosin and Its Coiled-Coil Structure

1972 ◽  
Vol 69 (12) ◽  
pp. 3800-3804 ◽  
Author(s):  
J. Sodek ◽  
R. S. Hodges ◽  
L. B. Smillie ◽  
L. Jurasek
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Coiled Coil ◽  
Coil Structure

Tektin B1 from ciliary microtubules: primary structure as deduced from the cDNA sequence and comparison with tektin A1

1993 ◽  
Vol 106 (3) ◽  
pp. 909-918 ◽  
Author(s):  
R. Chen ◽  
C.A. Perrone ◽  
L.A. Amos ◽  
R.W. Linck
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Sequence Homology ◽  
Molecular Design ◽  
Consensus Sequence ◽  
Coiled Coil ◽  
Predicted Amino Acid Sequence ◽  
Mitotic Spindles ◽  
Intermediate Filament Proteins ◽  
Duplication Events

Tektins are a class of proteins that form filamentous polymers in the walls of ciliary and flagellar microtubules, and they may also be present in centrioles, centrosomes and mitotic spindles. We report here the cloning and sequencing of a cDNA for ciliary tektin B1. Comparison of the predicted amino acid sequence of tektin B1 with the previously published sequence for tektin A1 reveals several features that better define this class of proteins. Like tektin A1, the central region of the tektin B1 polypeptide chain is predicted to form a coiled-coil rod, consisting of four major alpha-helical regions that are separated by non-helical linkers. Between the central rod domains of tektins A and B there is a 34%/20% amino acid sequence identity/similarity, including equivalent 50-residue segments containing 36 identities, and a high probability of long-range structural homology. The tektin polypeptide chains are divided into two major segments that have significant sequence homology to each other, both within a given tektin chain and between tektins A and B, indicative of gene duplication events. The tektins have a secondary structure and molecular design similar to, but a low primary sequence homology with, intermediate filament proteins. Unlike tektin A1, tektin B1 lacks any part of the C-terminal IFP consensus sequence.

scholarly journals Bovine filensin possesses primary and secondary structure similarity to intermediate filament proteins.

1993 ◽  
Vol 121 (4) ◽  
pp. 847-853 ◽  
Author(s):  
F Gounari ◽  
A Merdes ◽  
R Quinlan ◽  
J Hess ◽  
P G FitzGerald ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Secondary Structure ◽  
Intermediate Filament ◽  
Tandem Repeats ◽  
Phosphorylation Site ◽  
Intermediate Filament Proteins ◽  
Terminal Domain ◽  
Structure Similarity

The cDNA coding for calf filensin, a membrane-associated protein of the lens fiber cells, has been cloned and sequenced. The predicted 755-amino acid-long open reading frame shows primary and secondary structure similarity to intermediate filament (IF) proteins. Filensin can be divided into an NH2-terminal domain (head) of 38 amino acids, a middle domain (rod) of 279 amino acids, and a COOH-terminal domain (tail) of 438 amino acids. The head domain contains a di-arginine/aromatic amino acid motif which is also found in the head domains of various intermediate filament proteins and includes a potential protein kinase A phosphorylation site. By multiple alignment to all known IF protein sequences, the filensin rod, which is the shortest among IF proteins, can be subdivided into three subdomains (coils 1a, 1b, and 2). A 29 amino acid truncation in the coil 2 region accounts for the smaller size of this domain. The filensin tail contains 6 1/2 tandem repeats which match analogous motifs of mammalian neurofilament M and H proteins. We suggest that filensin is a novel IF protein which does not conform to any of the previously described classes. Purified filensin fails to form regular filaments in vitro (Merdes, A., M. Brunkener, H. Horstmann, and S. D. Georgatos. 1991. J. Cell Biol. 115:397-410), probably due to the missing segment in the coil 2 region. Participation of filensin in a filamentous network in vivo may be facilitated by an assembly partner.

scholarly journals Type II intermediate-filament proteins from wool. The amino acid sequence of component 5 and comparison with component 7c

1992 ◽  
Vol 282 (1) ◽  
pp. 291-297 ◽  
Author(s):  
L G Sparrow ◽  
C P Robinson ◽  
J Caine ◽  
D T W McMahon ◽  
P M Strike
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Intermediate Filament ◽  
Sequence Similarity ◽  
British Library ◽  
Intermediate Filament Protein ◽  
Type Ii ◽  
Blocking Group ◽  
Intermediate Filament Proteins ◽  
Merino Wool

Component 5 is one of the four type II intermediate-filament proteins found in the hard keratin wool. It was isolated as the S-carboxymethyl derivative from Merino wool and its amino acid sequence was determined by manual and automatic sequencing of peptides produced by chemical and enzymic cleavage. Component 5 is an N-terminally blocked molecule of 503 residues and Mr (not including the blocking group) of 56,600. The blocking group has not been identified. The amino acid sequence of component 5 shows 77% sequence identity with that of component 7c, another type II wool intermediate-filament protein [Sparrow, Robinson, McMahon & Rubira (1989) Biochem. J. 261, 1015-1022]. The sequence similarity extends from the N-termini of the two molecules to residue 459 (component 5 sequence); however, there is no recognizable sequence similarity in the remaining C-terminal 43 amino acid residues. Details of procedures used in determining the sequence of component 5 have been deposited as a Supplementary Publication SUP 50168 (80 pages) at the British Library Document Supply Centre, Boston Spa, Wetherby, West Yorkshire, LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1992) 281, 5. The information comprises: (1) details of chemical and enzymic methods used for cleavage of component 5, peptide CN1, the peptide mixture CN2/3 and various other peptides, (2) details of the procedures used for the fractionation and purification of peptides from (1), including Figures showing the elution profiles from the chromatographic steps used, and (3) details of the method used to determine the C-terminal sequence of component 5.

scholarly journals Cystatin. Amino acid sequence and possible secondary structure

1984 ◽  
Vol 217 (3) ◽  
pp. 813-817 ◽  
Author(s):  
C Schwabe ◽  
A Anastasi ◽  
H Crow ◽  
J K McDonald ◽  
A J Barrett
Keyword(s):  
Amino Acid ◽  
Secondary Structure ◽  
Amino Acid Sequence ◽  
Tight Binding ◽  
Alpha Helix ◽  
Egg White ◽  
Striking Similarity ◽  
Cysteine Proteinases ◽  
Amino Acid Residues ◽  
Beta Structure

The amino acid sequence of cystatin, the protein from chicken egg-white that is a tight-binding inhibitor of many cysteine proteinases, is reported. Cystatin is composed of 116 amino acid residues, and the Mr is calculated to be 13 143. No striking similarity to any other known sequence has been detected. The results of computer analysis of the sequence and c.d. spectrometry indicate that the secondary structure includes relatively little alpha-helix (about 20%) and that the remainder is mainly beta-structure.

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