scholarly journals Amino acid sequences of α-helical segments from S-carboxymethylkerateine-A. Statistical analysis

1978 ◽  
Vol 173 (2) ◽  
pp. 387-391 ◽  
Author(s):  
T C Elleman ◽  
W G Crewther ◽  
J Van Der Touw

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.

1972 ◽  
Vol 50 (3) ◽  
pp. 330-343 ◽  
Author(s):  
R. S. Hodges ◽  
L. B. Smillie

Amino acid analyses of tropomyosin have shown three cysteine residues per mole (M.W. 70 000) of tropomyosin. The cysteine content was determined by cysteic acid determinations, incorporation of 14C-labelled iodoacetic acid into the protein, and the analysis of S-carboxymethylcysteine after acid hydrolysis. The isolation of three unique cysteinyl peptides is incompatible with a homogeneous tropomyosin preparation of two chemically identical subunits. The amino acid sequences reported in this study indicate a regular repeat of hydrophobic residues as required by the inter-chain packing of a coiled-coil structure.


1978 ◽  
Vol 173 (2) ◽  
pp. 365-371 ◽  
Author(s):  
W G Crewther ◽  
A S Inglis ◽  
N M McKern

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.


Blood ◽  
2000 ◽  
Vol 95 (4) ◽  
pp. 1435-1442 ◽  
Author(s):  
Edward M. Conway ◽  
Saskia Pollefeyt ◽  
Jan Cornelissen ◽  
Inky DeBaere ◽  
Marta Steiner-Mosonyi ◽  
...  

Survivin is a member of the inhibitor of apoptosis protein (IAP) family that is believed to play a role in oncogenesis. To elucidate further its physiologic role(s), we have characterized the murinesurvivin gene and complementary DNA (cDNA). The structural organization of the survivin gene, located on chromosome 11E2, is similar to that of its human counterpart, both containing 4 exons. Surprisingly, 3 full-length murine survivin cDNA clones were isolated, predicting the existence of 3 distinct survivin proteins. The longest open reading frame, derived from all 4 exons, predicts a 140-amino acid residue protein, survivin140, similar to human survivin, which contains a single IAP repeat and a COOH-terminal coiled-coil domain that links its function to the cell cycle. A second cDNA, which retains intron 3, predicts the existence of a 121-amino acid protein, survivin121 that lacks the coiled-coil domain. Removal of exon 2-derived sequences by alternative pre-messenger RNA (mRNA) splicing results in a third 40-amino acid residue protein, survivin40, lacking the IAP repeat and coiled-coil structure. Predictably, only recombinant survivin140 and survivin121 inhibited caspase-3 activity. All 3 mRNA species were variably expressed during development from 7.5 days postcoitum. Of the adult tissues surveyed, thymus and testis accumulated high levels of survivin140 mRNA, whereas survivin121-specific transcripts were detected in all tissues, while those representing survivin40 were absent. Human counterparts to the 3 survivin mRNA transcripts were identified in a study of human cells and tissues. The presence of distinct isoforms of survivin that are expressed differentially suggests that survivin plays a complex role in regulating apoptosis.


1986 ◽  
Vol 238 (1) ◽  
pp. 305-308 ◽  
Author(s):  
D A D Parry ◽  
J F Conway ◽  
P M Steinert

Analysis of the amino acid sequences of lamins A and C has revealed that each chain has an almost continuous heptad-containing coiled-coil domain containing structural regularities in the linear disposition of the acidic and the basic residues. The data suggest that the lamin molecules are two-stranded ropes, that the two chains are parallel to one another and in axial register, and that the molecules aggregate in vivo through periodic ionic interactions. These results indicate that significant changes in stability of the nuclear envelope may be achieved between interphase and mitosis through changes in the degree of phosphorylation of the lamin proteins.


1992 ◽  
Vol 8 (1) ◽  
pp. 87-89 ◽  
Author(s):  
F. Chen ◽  
D. Puett

ABSTRACT The heterodimer, human chorionic gonadotrophin (hCG), contains an a subunit that is common to the glycoprotein hormones and a hormone-specific β subunit. A comparison of all known β amino acid sequences shows that an aspartic acid at position 99 (with the numbering scheme for hCG-β) is one of the seven non-Cys invariant residues. Using site-directed mutagenesis we have replaced hCG-β Asp99 with Arg. Chinese hamster ovary cells, containing a stably integrated gene for bovine a subunit, were transiently transfected with plasmids containing wild-type and mutant hCG-β cDNAs. The Arg99 β mutant associated with the a subunit, but the resulting heterodimer failed to enhance intracellular cyclic AMP production in a gonadotrophin-responsive transformed murine Leydig cell line. Thus, a single amino acid residue replacement in this glycosylated heterodimer containing 237 amino acid residues is sufficient to abolish activity.


1980 ◽  
Vol 87 (1) ◽  
pp. 227-236 ◽  
Author(s):  
Sadao WAKABAYASHI ◽  
Toshiharu HASE ◽  
Keishiro WADA ◽  
Hiroshi MATSUBARA ◽  
Koichi SUZUKI

1988 ◽  
pp. 145-155 ◽  
Author(s):  
L. G. Sparrow ◽  
L. M. Dowling ◽  
V. Y. Loke ◽  
P. M. Strike

1978 ◽  
Vol 173 (2) ◽  
pp. 373-385 ◽  
Author(s):  
K H Gough ◽  
A S Inglis ◽  
W G Crewther

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.


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