alpha helix


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alpha helix

[′al·fə ′hē·liks]
(cell and molecular biology)
A spatial configuration of the polypeptide chains of proteins in which the chain assumes a helical form, 0.54 nanometer in pitch, 3.6 amino acids per turn, presenting the appearance of a hollow cylinder with radiating side groups.
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The highest improvement is 0.028, which is reached when 4x4 submatrices, 30 models, and the "Alpha helix propensity" are used.
The secondary protein structure a polypeptide is the small part and polypeptide sequence, curls up into an alpha helix or beta pleated sheets.
[DELTA]201 NcGRA9-HA, missing the PEST domain and a hydrophobic alpha helix, was never found in the vacuolar space but was detectable in the paranuclear region of the intravacuolar tachyzoites.
Alpha helix and helix 3/10 are, in general, underrepresented around Asp residues involved in [Mn.sup.2+] coordination.
For example, coil between beta strand and alpha helix (BCH) is enriched by Ser and Thr, while coil between alpha helix and beta strand (HCB) is enriched by Arg and Lys.
Secondary structures (alpha helix and beta sheets) in these sequences that could give indications oftheir importance were sought by using the APSSP2 algorithm (http:// www.imtech.res.in/raghava/apssp2/).
39813.1 39853.2 6612.6 6582.5 pI of Domain 7.76 7.77 5.55 5.55 Half-Life 1.9 hrs 1.9 hrs 30 hrs 30 hrs Instability index 76.06 76.18 44.10 38.14 Hydropathicity -0.466 -0.471 -0.077 -0.120 Alpha helix 12.87% 16.09% 1.64% 0.00% Extended strand 7.77% 7.77% 42.62% 42.62% Beta turn 0.27% 0.27% 4.92% 4.92% Random coil 79.09% 75.87% 50.82% 52.46% Stability Stable unstable unstable stable Features Neogenin_C N M Mol.
Plots generated in this study clearly indicate that there are geometric shifts in the polypeptides as a function of the form in which they are minimized, and compares polyalanines with 50 residues for a sheeted structure (five parallel sheets), an alpha helix and a beta helix, with the alpha structure showing the widest range of angles.
Together, Watson and Crick aspired to solve the structure of DNA by model building, just as Pauling had done for the alpha helix in proteins.
We returned to Prince William Sound in June of the same year aboard the University of Alaska's 140-foot research vessel Alpha Helix, led by my mentor, Professor John Oliver, known as "the galactic wizard," the archetype of "can do" biologists, and a true underwater naturalist with a teach-by-doing philosophy.
His elucidation of the "alpha helix" structure of proteins was widely applauded as a significant contribution, but the "right answer" to the riddle of replication came from Cambridge scientists Francis Crick and James Watson, who announced their DNA discoveries in 1953.
Table 1 shows the ROC score when the 'Alpha helix propensity' and the combination of indices 'pK (-COOH)' and 'Atom based hydrophobic moment' are used.