Anti-Tri-methyl Lysine polyclonal antibody

An extraordinary micro-structural similarity between squid sucker teeth and the egg shell of a terrestrial planarian worm has been reported, but to date only the amino acid content of the squid sucker tooth has been available. This prompted us to analyse the amino acid content of the planarian egg shell. Although both share an absence of detectable chitin and metal ions and both possess relatively high amounts of the amino acids GLY and HIS, the planarian egg shell is considerably richer in GLU, LYS and ASP. Most dramatic was the difference in TYR, which was the second most abundant amino acid in the squid, but hardly featured at all in the planarian egg shell. In the light of these new findings the different functional roles that the structures in question play in the lives of the two taxa are discussed. An EDS-analysis revealed clear C, N, and O peaks and additional very small peaks less than 0.1w% suggesting the presence of one or both S and Cl.

Little is known experimentally about the detailed orientation of membrane-bound maculatin 1.1 (Mac1), an antimicrobial peptide from the skin secretions of Australian tree frogs. In this work multiple N-15-labelled or H-2-labelled Mac1 with dodecylphosphocholine (DPC) micelles and isotropic DMPC/DHPC (q = 0.5) bicelles were investigated by solution NMR, circular dichroism (CD) spectroscopy, neutron reflectometry and molecular dynamics (MD) simulations in explicit solvent. In buffer, the N-15-H-1 HSQC and CD spectra were indicative of the peptide being random coiled. In the presence of micelles or isotropic bicelles, a unique and helical peptide structure that was confirmed by CD was found. The titration of the soluble paramagnetic agent gadolinium (GdDTPA) into the Mac1-DPC solution led to enhanced relaxation of all N-15 labelled residues. The peptide N-terminus was more exposed to Gd-DTPA than the C-terminus in micelles, while only the Gly-4 and Ala-18 resonances were significantly reduced in the presence of isotropic bicelles. MD simulations of Mac1 fully inserted into a DPC micelle converged towards a solvent exposed orientation and a topology where Mac1 was wrapped around the DPC micelle with the more hydrophobic side facing inward. MD simulations of Mac1 fully inserted into a phosphatidylcholine (PC) bilayer converged towards a kinked transmembrane orientation with water molecules penetrating around Lys-8. A deuterium labelled Mac1 used in neutron reflectometry experiments suggested a preferred orientation in zwitterionic PC bilayers. These results give insight into the membrane disrupting activity of Mac1 against cell membranes.