(n.) A nonplane curve whose tangents are all equally inclined to a given plane. The common helix is the curve formed by the thread of the ordinary screw. It is distinguished from the spiral, all the convolutions of which are in the plane.
(n.) A caulicule or little volute under the abacus of the Corinthian capital.
(n.) The incurved margin or rim of the external ear. See Illust. of Ear.
(n.) A genus of land snails, including a large number of species.
Example Sentences:
(1) The presence of a few key residues in the amino-terminal alpha-helix of each ligand is sufficient to confer specificity to the interaction.
(2) The elongation of helix III with the addition of helix II at the N-terminus somewhat stabilizes the ordered structure.
(3) The C-terminal sequence contains an amphiphilic alpha-helix of four turns which lies on the surface of the beta-barrel.
(4) The chiral intercalators, at micromolar concentrations, inhibit the reaction of EcoRI, but for each enantiomeric pair it is the lambda enantiomer, which binds only poorly to a B-DNA helix, that inhibits EcoRI preferentially.
(5) The melting profile exhibited two transitions--one at about 35 degrees C and one above 50 degrees C. Our spectral data showed that helices I and II were stable during the first transition, and agreed with other data that helix III was the most likely helix to have melted.
(6) The helix axes, penetrating the hydrophobic region of the bilayers, were oriented neither parallel nor perpendicular to the membrane normal.
(7) The structure of the Z-helix antigen was confirmed by circular dichroism (CD) and U.V.
(8) Conformational predictions based on these sequences confirm their structural homology and indicate the probable existence of two beta-turns, one beta-chain and a long alpha-helix in them.
(9) The nogalose and aminoglucose sugars lie in the minor and major grooves, respectively, of the distorted B-DNA double helix.
(10) The latter, which is external and solvent accessible, is associated with a distortion in the alpha-helix centered around Tyr33 which consists of a significant increase in the CO(i-4)-N(i) and CO(i-4)-NH(i) distances relative to those in the rest of the helix, as well as a significant departure in the phi, psi angles of Tyr33 relative to regular helical geometry.
(11) The AFB1 moiety is face-stacked in the major groove with its long axis approximately perpendicular to the helix axis.
(12) MP8 also was conformed as an alpha-helix, but was amphipatic in the sense that the N-terminal half of the molecule was hydrophilic and the C-terminal half hydrophobic.
(13) A lectin, Helix pomatia agglutinin (HPA), was planted at the surface of rat GEN by the perfusion of the isolated left kidney with neuraminidase (NRD) and HPA.
(14) As a basis for the discussion a possible structure for the DNA complex of the phenylated neutral red is considered in which the extra phenyl ring at N-5 of the phenazinium system, protrudes into the large groove of the DNA helix while the tricyclic part of the ligand is inserted between the DNA base-pairs.
(15) The opsin mutations included reversal of a charged pair conserved in all G protein-coupled receptors at the cytoplasmic border of the third transmembrane helix (mutant CD1), replacement of 13 amino acids in the second cytoplasmic loop (mutant CD2), and deletion of 13 amino acids from the third cytoplasmic loop (mutant EF1).
(16) The remaining 26 independently isolated second-site suppressor mutations all mapped within the amino-terminal DNA binding domain of LexA, at positions 22 (situated in the turn between helix 1 and helix 2) and positions 57, 59, 62, 71 and 73.
(17) In subsequent steps, unassociated Y' directs the synthesis of the complementary oligopurine (R') strand forming a new double helix Y'R' that may direct the synthesis of an oligopyrimidine strand, Y, that is expected to be identical to the first strand that started the whole sequence.
(18) Z-DNA antigen was prepared against poly(dG-dC).poly(dG-dC), which had been converted to the Z-helix conformation in high salt and then stabilized by bromination.
(19) Incubation and heating of the polymers in 1 mM Mn2+ caused the spectral shift reported for the left-handed Z-DNA conformation in the alternating copolymer and the change reported for the triple helix in the homopolymer.
(20) To investigate the ability of a protein to accommodate potentially destabilizing amino acid substitutions, and also to investigate the steric requirements for catalysis, proline was substituted at different sites within the long alpha-helix that connects the amino-terminal and carboxyl-terminal domains of T4 lysozyme.
Spiral
Definition:
(a.) Winding or circling round a center or pole and gradually receding from it; as, the spiral curve of a watch spring.
(a.) Winding round a cylinder or imaginary axis, and at the same time rising or advancing forward; winding like the thread of a screw; helical.
(a.) Of or pertaining to a spiral; like a spiral.
(a.) A plane curve, not reentrant, described by a point, called the generatrix, moving along a straight line according to a mathematical law, while the line is revolving about a fixed point called the pole. Cf. Helix.
(a.) Anything which has a spiral form, as a spiral shell.
Example Sentences:
(1) Digestion is initiated in the gastric region by secretion of acid and pepsin; however, diversity of digestive enzymes is highest in the post-gastric alimentary canal with the greatest proteolytic activity in the spiral valve.
(2) Don't we by chance come across this reciprocal spiral perspective when two people distrust one another without actually showing it?
(3) A great deal of information about the spiral bacteria of the stomach has accumulated in the past 5 years.
(4) Somalia has faced drought; famine; decades of conflict, now involving the Islamist rebels of al-Shabaab among other groups; the absence of an effective, central authority; and spiralling food prices.
(5) Spiral neurons, their fibers and endings as well as inner and outer hair cells express NSE in the isolated organ of Corti in culture.
(6) The binding sites were mainly located on the stereocilia, the cuticular plate of hair cells, the head plates of Deiters' cells, fibrous structures in pillar cells, in the spiral limbus and tectorial membrane and basilar membrane, plasma membranes, mitochondria and the chromatin of various kinds of cells.
(7) When normalized with respect to scala cross-section, the process of tracer movement across the spiral ligament is similar in the basal and third turns.
(8) Tangent-screen studies uncovered neurasthenic spiral fields superimposed on hysterical tubular contractions of both eyes.
(9) The phi-model also gives the noble numbers and moreover orders them in a way that establishes connections with the morphogenetic principles used in models for pattern generation; the order has to do with the relative frequencies of the spiral patterns in nature.
(10) The row had been inflamed over the weekend by a series of leaks about the spiralling price of Gove's free schools and high costs of Clegg's free school meals, giving Labour ammunition to attack the government's education policy in Westminster.
(11) Spiral-like primary dendrites were found and the orientation of secondary dendrites changed.
(12) The main uterine, radial and spiral arteries were identified in all patients.
(13) In animals receiving passive (unstimulated) implants, morphometric analysis of spiral ganglion cell density showed no significant difference in ganglion cell survival between the implanted cochleas and the contralateral control ears.
(14) Later, these vacuoles were divided into numerous vesicular spiral formation-centers, producing micronemes at the apical pole of young merozoites.
(15) During more extended exposure (60 and 90 days) the changes in hair cells of the spiral organ, which included nuclear deformation and disintegration of chromatin, mitochondria and endoplasmic reticulum membranes, became irreversible and caused the decay of injured cells.
(16) The company's value lies in its FM licence for London, with the audience for its national AM licence spiralling downwards in recent years.
(17) The spiral reinforcement at the same time prevents compression of the vein by surrounding cicatricial tissue as well as an aneurysmatic extension of the transplant.
(18) The intensity-measuring device in both apparatuses has a mobile disk attached to a motionless axis by a spiral spring; the clamps have fixing screws in the butts of a spong.
(19) The balance is fragile and the threat of a spiral of decline is not an idle one.
(20) They ran in a spiral pattern in the distal part of the middle cerebral artery.