Figure 1
From: Efficient transdermal delivery of functional protein cargoes by a hydrophobic peptide MTD 1067
Physicochemical properties of MTD 1067. (a) Optimization and modification of synthetic MTD peptides designed based on hydrophobic regions in signal peptide sequences. MTD 1067 was modified from one of the first-generation MTDs, MTD 067 (AAAPAVAA) to increase biological membrane accessibility and permeability30‚58. The first generation of synthetic MTDs was developed by modifying the hydrophobic region in the signal sequences of various proteins to contain non-polar amino acids, such as alanine, valine, leucine, isoleucine, and proline, in different combinations to increase affinity with the hydrophobic lipid bilayer of the intracellular plasma membrane. Subsequently, positively charged hydrophilic amino acids, such as arginine, histidine, and lysine, were additionally introduced into the conventional hydrophobic MTDs to increase the accessibility of peptides to the negatively charged surface of the cell membrane. The N-terminal was also modified to contain methionine, which is the universal start codon in the signal peptide. The secondary structure of MTD 1067 was predicted using a de novo peptide structure prediction tool, PEP-FOLD3. (b) Alpha helix structure and physicochemical properties of MTD 1067. The helix wheel property and secondary structure of MTD 1067 were analyzed using HELIQUEST (http://heliquest.ipmc.cnrs.fr/)59 and PEP-FOLD 3.5 (https://mobyle.rpbs.univ-paris-diderot.fr/)60,61,62, respectively.
