Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04626 (erbB-2)
 5,251 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mixtures of dicaproyl- (DC), dimyristoyl- (DM) and 1-tetradecanoyl-2-biphenylbutanoyl-(TBB) phosphatidylcholine (PC) in water produce bicelle membranes that are oriented by magnetic fields. DMPC/DCPC systems orient such that their membrane plane is parallel to the magnetic field, whereas for TBBPC/DCPC, the plane is perpendicular to the field. Partial temperature-composition-hydration diagrams are established using solid-state 31P-NMR. DMPC/DCPC bicelles exist on a large range of composition but on a narrow temperature domain (25-45 degrees C). At converse, TBBPC/DCPC form bicelles on a narrow compositional range but over a large temperature span (10-70 degrees C). The TBBPC/DCPC bicelles are shown to be a very powerful potential tool to study the orientation of hydrophobic helices in membranes using wide line 15N-NMR. The DMPC/DCPC system that undergoes a micelle-to-bicelle transition on going from 10 degrees C to 40 degrees C may be used with circular dichroism to study the state of association of hydrophobic helices within the membrane. Results suggest that the transmembrane fragment of the neu/erbB-2 receptor is monomeric in micellar medium and dimeric/multimeric in bicelle membranes.
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PMID:Bicelle membranes and their use for hydrophobic peptide studies by circular dichroism and solid state NMR. 1596 Dec 33

Solid-phase syntheses of the hydrophobic peptides Neu(TM35) ((1)EQRASPVTFIIATVVGVLLFLILVVVVGILIKRRR(35)) and Neu*(TM35) ((1)EQRASPVTFIIATVEGVLLFLILVVVVGILIKRRR(35)), corresponding to the native and mutated (V15E) transmembrane domain of the neu/erbB-2 tyrosine kinase receptor, respectively, were accomplished using Fmoc chemistry. The use of a new resin and cleavage and purification conditions led to large increases in yields and peptide purity. Two (15)N-labelled versions of both wild type and mutated peptides were also synthesized. Approximately 20-40 mg of peptide was obtained using a small-scale synthesis, whereas ca 100 mg of pure peptide was collected on a medium scale. Peptide purity, as monitored by HPLC and mass spectrometry, ranged from 95 to 98% for the six peptides synthesized. Secondary structure as determined by UV circular dichroism (CD) in trifluoroethanol (TFE) showed ca 74% alpha-helical content for the native peptide and ca 63% for that bearing the mutation. Secondary structure of Neu(TM35) was retained in DMPC (dimyristoylphosphatidylcholine)/DCPC (dicaproylphosphatidylcholine) membrane bicelles, and evidences for dimers/oligomers in the lipid bilayer were found.
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PMID:Revisited and large-scale synthesis and purification of the mutated and wild type neu/erbB-2 membrane-spanning segment. 1628 25