Browse
Submit Data
Databases
API
Help

Dataset Information

8 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

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

ABSTRACT: 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.

SUBMITTER: Crewther WG

PROVIDER: S-EPMC1185788 | biostudies-other | 1978 Aug

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Amino acid sequences of alpha-helical segments from S-carbosymethylkerateine-A. Complete sequence of a type-I segment.

Project description:The amino acid sequence of a type-I helical segment from the low-sulphur protein (S-carboxymethylkerateine-A) of wool was determined by combining automatic and manual-sequencing data. Whereas in the type-II helical segment most of the cationic groups occur in pairs, 11 of the 22 anionic residues in the sequence of the type-I segment were situated next to a second anionic residue. This suggests possible interactions between type-I and type-II helical segments in alpha-keratin. As observed with the sequence of a type-II helical segment a model constructed on 3.6 residues per turn of helix shows a line of hydrophobic residues along the helix, thereby supporting the physicochemical evidence that the molecule is predominantly helical and forms part of a coiled-coil structure. Examination of the sequence data by predictive methods indicates the possibilty of extensive sections of alpha-helix interspersed with discontinuities. The molecule contains a number of regions with peptide sequences identical with those found by other workers after enzymic digestion of fractions from oxidized wool.

| S-EPMC1185789 | biostudies-other

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

Project description:1. Amino acid-sequence studies were done on a peptide of mol.wt. approx. 12500 that was isolated from the highly helical fragments obtained by partial chymotryptic digestion of the low-sulphur proteins (S-carboxymethylkerateine-A) from wool. 2. The peptides obtained by tryptic and chymotryptic digestion of this large peptide were separated by ion-exchange chromatography on DEAE-cellulose at pH8.5 with an (NH4)(2)CO(3) concentration gradient and, where necessary, purified further by paper electrophoresis. 3. Determination of the sequences of many of these peptides showed that a high proportion of the cationic residues occurs in pairs. 4. Although two of the four S-carboxymethylcysteine residues are located in what appears to be a non-helical region near the N-terminus the other two S-carboxymethylcysteine residues occur in or near sequences suggesting a helical conformation. 5. Some peptides were obtained, in low yields, that appeared to be homologues of more major ones. These suggest either homologies in the helical portions of the low-sulphur proteins or the presence of closely related amino acid sequences in helical regions of completely different origins. 6. A partial sequence of the complete peptide is proposed.

| S-EPMC1185787 | biostudies-other

Amino acid sequences of alpha-helical segments from S-carboxymethylkerateine-A. Statistical analysis.

Project description:The distribution of the different types of amino acid residue within two helical segments isolated from the low-sulphur fraction of wool keratin was examined for periodicity and larger sequence repeats. Both were detected, the former corresponding to the geometry of the proposed coiled=coil structure and the latter suggesting a distant gene duplication, though the existence of the repeat might equally well be related to interactions within the microfibril.

| S-EPMC1185790 | biostudies-other

A Sequential Segment Based Alpha-Helical Transmembrane Protein Alignment Method.

Project description:Alpha-helical transmembrane protein (?TMP) is one of the two major categories of transmembrane protein (TMP). They are abundant existing in eukaryotic cells and involved in many biological processes. The special physicochemical properties, the structures of ?TMP are hard to be experimentally solved, but ?TMP's sequential segments are important to determine their conformations, so that TM-specific alignment is necessary to benefit their structure prediction. We used segment information extracted from topology structure and evolutionary information as features to implement a ?TMP Segment Alignment method (TMSA). The method was trained using one non-redundant dataset and tested using another non-redundant dataset. Comparing the results to a general alignment method HHalign, TMSA achieved higher alignment accuracy, and easier to recognize the fold of ?TMPs.

| S-EPMC6036746 | biostudies-literature

Environment- and sequence-dependence of helical type in membrane-spanning peptides composed of ?3-amino acids.

Project description:Transmembrane (TM) ?-peptides comprised of acyclic ?(3)-amino acids demonstrate equilibrium between 12- and 14-helical structures in an environment- and sequence-dependent manner. Circular dichroism (CD) spectra of TM ?(3)-peptides may be described as linear combinations of the 12- and 14-helical CD spectra. The apparent malleability of ?(3)-substituted acyclic ?-peptides has practical implications for foldamer design, as it suggests that both the 14-helix and 12-helix might be reasonable platforms for molecular recognition.

| S-EPMC3124938 | biostudies-literature

Complete genome sequences of highly divergent Torque teno virus type II from swine herds.

Project description:Through routine and nested PCR amplifications, four complete genome sequences of porcine Torque teno virus (TTV) type II were obtained from swine herds. By comparison with the TTV genome sequences deposited in GenBank, we found the most divergent types so far described. The level of genetic diversity between these genomes is higher than would be expected within a single virus species. A nucleotide and amino acid phylogenetic tree was constructed.

| S-EPMC3486482 | biostudies-literature

Complete Genome Sequences of Two Staphylococcus aureus Sequence Type 5 Isolates from California, USA.

Project description:Staphylococcus aureus causes a variety of human diseases ranging in severity. The pathogenicity of S. aureus can be partially attributed to the acquisition of mobile genetic elements. In this report, we provide two complete genome sequences from human clinical S. aureus isolates.

| S-EPMC5374241 | biostudies-literature

Scalable synthesis and coupling of quaternary α-arylated amino acids: α-aryl substituents are tolerated in α-helical peptides.

Project description:Quaternary amino acids are important tools for the modification and stabilisation of peptide secondary structures. Here we describe a practical and scalable synthesis applicable to quaternary alpha-arylated amino acids (Q4As), and the development of solid-phase synthesis conditions for their incorporation into peptides. Monomeric and dimeric α-helical peptides are synthesised with varying degrees of Q4A substitution and their structures examined using biophysical methods. Both enantiomers of the Q4As are tolerated in folded monomeric and oligomeric α-helical peptides, with the (R)-enantiomer slightly more so than the (S).

| S-EPMC8278958 | biostudies-literature

Amino acid sequence of the N-terminal non-collagenous segment of dermatosparactic sheep procollagen type I.

Project description:The non-collagenous N-terminal segment of type I procollagen from dermatosparactic sheep skin was isolated in the form of the peptide Col 1 from a collagenase digest of the protein. The peptide has a blocked N-terminus, which was identified as pyrrolid-2-one-5-carboxylic acid. Appropriate overlapping fragments were prepared from reduced and alkylated peptide Col 1 by cleavage with trypsin at lysine, arginine and S-aminoethyl-cysteine residues and by cleavage with staphylococcal proteinase at glutamate residues. Amino acid sequence analysis of these fragments by Edman degradation and mass spectrometry established the whole sequence of peptide Col 1 except for a peptide junction (7--8) and a single Asx residue (44), and demonstrated that peptide Col 1 consists of 98 amino acid residues. The N-terminal portion of peptide Col 1 (86 residues) shows an irregular distribution of glycine, whereas the C-terminal portion (12 residues) possesses the triplet structure Gly-Xy and is apparently derived from the precursor-specific collagenous domain of procollagen. The central region of the peptide contains ten cysteine residues located between positions 18 and 73 and shows alternating polar and hydrophobic sequence elements. The regions adjacent to the cysteine-rich portion have a hydrophilic nature and are abundant in glutamic acid. The data are consistent with previous physicochemical and immunological evidence that distinct regions at the N- and C-termini of the non-collagenous domain possess a less rigid conformation than does the central portion of the molecule.

| S-EPMC1186672 | biostudies-other

Complete Genome Segment Sequences of Tomato Chlorotic Spot Virus from Peanut in Haiti.

Project description:Tomato chlorotic spot virus (TCSV) is emerging as a significant constraint to vegetable and legume crops in the Americas. The complete genome sequence of a TCSV isolate naturally infecting peanut (Arachis hypogea) in Haiti was determined in the effort to build epidemiological knowledge of the virus.

| S-EPMC6498236 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data