SummaryNatural processes within the body are modulated almost exclusively by the interaction of specific amino acid sequences, either as peptides or as subsections of proteins. With respect to skin, proteins and peptides are involved in the modulation of cell proliferation, cell migration, inflammation, angiogenesis, melanogenesis, and protein synthesis and regulation. The creation of therapeutic or bioactive peptide analogs of specific interactive sequences has opened the door to a diverse new field of pharmaceutical and active cosmetic ingredients for the skincare industry. Here, we describe the origin of such sequences, their role in nature, their application to dermatology, as well as the advantages and challenges posed by this new technology.
Laspartomycin was originally isolated and characterized in 1968 as a lipopeptide antibiotic related to amphomycin. The molecular weight and structure remained unknown until now. In the present study, laspartomycin was purified by a novel calcium chelate procedure, and the structure of the major component (1) was determined. The structure of laspartomycin C (1) differs from that of amphomycin and all related antibiotics as a result of its peptide region being acidic rather than amphoteric and the amino acid branching into the side chain being diaminopropionic rather than diaminobutyric. In addition, the fatty acid side chain is 2,3-unsaturated compared to 3,4-unsaturated for amphomycin and other related antibiotics. Calcium ion addition to stabilize a particular conformer was found to be important for an enzymatic deacylation of the antibiotic. A peptide resulting from the deacylation was critical for chemical structure determination by NMR studies, which also involved addition of calcium ions to stabilize a conformer.
The 'matrikine' concept claims that processing of the precursors for collagen results in the formation of peptides such as KTTKS which in turn augments extracellular matrix (ECM) production. In the present study, we show the development of an anti-ageing active from an in silico approach by molecular design resulting in the tetrapeptide GEKG derived from ECM proteins. The efficacy of the peptide to significantly induce collagen production of the protein level and mRNA level has been demonstrated in vitro in human dermal fibroblasts and in vivo in a double-blind, randomized, placebo-controlled study enroling 10 volunteers with an average age of 48.2 years. The effect of GEKG on facial wrinkles was studied in 30 volunteers using state of the art fringe projection, which allows determination of surface roughness in three-dimensions. Here, only GEKG but not the placebo was able to significantly decrease skin roughness as a measure for wrinkles.
The monomer units in the Escherichia coli andStaphylococcus aureus cell wall peptidoglycans differ in the nature of the third amino acid in thel-alanyl-γ-d-glutamyl-X-d-alanyl-d-alanine side chain, where X is meso-diaminopimelic acid orl-lysine, respectively. The murE gene fromS. aureus encoding the UDP-N-acetylmuramoyl-l-alanyl-d-glutamate:l-lysine ligase was identified and cloned into plasmid vectors. Induction of its overexpression in E. coli rapidly results in abnormal morphological changes and subsequent cell lysis. A reduction of 28% in the peptidoglycan content was observed in induced cells, and analysis of the peptidoglycan composition and structure showed that ca. 50% of themeso-diaminopimelic acid residues were replaced byl-lysine. Lysine was detected in both monomer and dimer fragments, but the acceptor units from the latter contained exclusivelymeso-diaminopimelic acid, suggesting that no transpeptidation could occur between the ɛ-amino group ofl-lysine and the α-carboxyl group ofd-alanine. The overall cross-linking of the macromolecule was only slightly decreased. Detection and analysis ofmeso-diaminopimelic acid- andl-lysine-containing peptidoglycan precursors confirmed the presence of l-lysine in precursors containing amino acids added after the reaction catalyzed by the MurE ligase and provided additional information about the specificity of the enzymes involved in these latter processes.
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