Mussel adhesive protein: permeability characteristics when used as a basement membrane

Structural and Biophysical Characterization of a Cyclic Bioadhesive With Cell Attachment Ability

Structural and cellular attachment analysis identified overall bent helical regions of adhesive peptides identified within mussel adhesive protein (MAP) capable of also attaching cells. DOPA (L-DOPA, 3,4-dihydroxyphenylalanine) is frequently identified and credited for the attachment ability of several marine proteins [Olivieri, MP, et al. (2002), Biofouling18, 149-159]. Newly designed cyclic peptides (DOPA-G-G-C-G-K-A-K-G-C [cyc-DOPA] & Y-G-G-C-G-K-A-K-G-C [cyc-Y]) derived from structurally conserved regions of several MAP peptides were examined to assist in the understanding of both surface and cellular attachment. Solution-state proton nuclear magnetic resonance (NMR) spectroscopy coupled with molecular modeling and dynamics revealed minimal differences in the structures of the proposed cellular attachment domain within these two peptides. Multiple attenuated internal reflection infrared (MAIR-IR) spectroscopy, ellipsometry and advancing contact angle analyses showed that formation of thin films by these peptides was L-DOPA and pH dependent. When compared to control surfaces, undifferentiated leukocyte cells (MOLT-4) significantly attached and spread onto films created from the cyc-DOPA. The culmination of these structural, biophysical and cellular attachment techniques reveal a conformation of cyc-DOPA that is capable of both adsorbing to surfaces and then attaching cells that spread. This work supports the sequence, K-A-K, as the cellular attachment domain, especially when held in a reliable structural conformation.,.

In vitro creation of amyloid fibrils from native and Arg124Cys mutated betaIGH3((110-131)) peptides, and its relevance for lattice corneal amyloid dystrophy type I

BetaIGH3 protein has been recently involved in the pathogenesis of blinding corneal diseases, some of which have characteristic amyloid corneal deposits. The 124 codon of the betaig-h3 gene seems to be crucial for the amyloidogenicity of the protein product. We presently report an in vitro system that reproducibly forms amyloid fibrils from betaIGH3((110-131)) derived peptides. We also assessed the differences in fibril formation of two 22-amino acid peptides centered on the 124 residue: the native form and the Arg124Cys peptide (mutation linked to lattice corneal amyloid dystrophy type 1). After dialysis of Arg124Cys peptide against PBS 1/15 M pH 7.4 for 72 hours, Congo red staining and electron microscopy demonstrated the presence of abundant material fulfilling the criteria of amyloid. Quantitative analysis with thioflavine T fluorescence studies confirmed the high capacity of Arg124Cys peptide to form amyloid fibrils when compared to the native form.

Nuclear magnetic resonance spectroscopy of mussel adhesive protein repeating peptide segment

Mussel adhesive protein (MAP) is the adhesive agent used by the common blue sea mussel (Mytilus edulis) to attach the animal to various underwater surfaces. It is generally composed of 75 to 85 repeating decameric units with the reported primary sequence NH2-Ala(1)-Lyst(2)-Pro(3)-Ser(4)-Tyr(5)-Hyp(6)-Hyp(7)-Thr(8)-DOPA( 9)- Lys(10)-COOH. This study examines this peptide's solution-state conformation using proton nuclear magnetic resonance (NMR) spectroscopy. NMR and molecular modeling of the decamer before and after molecular dynamics calculations in water suggests a conformation that retains an overall bent helix.