The beauty and the anti-ageing industry is focused on finding ways to augment the fibrillar proteins collagen and elastin embedded in an extracellular matrix in the dermal layer of the skin. A pentapeptide KTTKS, within the carboxy terminal propeptide of type I collagen is extensively used as an anti-ageing cosmetic ingredient. The proposed mechanism of action is tricking the body into believing that there is excessive collagen degradation so that collagen biosynthetic pathway is stimulated. I have blogged about the potential limitations in Skin Deep .
|B0005968 Collagen fibril forming in vitro (Photo credit: wellcome images)|
Yet another peptide called tetrapeptide - 21 is claimed to be superior to KTTKS in anti-ageing properties. They claim to have discovered this by using bioinformatics methodology.
Let me quote from a product brochure:
We used bioinformatic methods to identify highly repetitive amino acid motifs in several human ECM proteins to identify sequences with inherent anti-aging activities. Using the amino acid sequences of collagen I, II, III, IV, V, elastin, and proelastin, tetra-peptide sequences were identified by their frequency of occurrence.
|Beauty box1886 (Photo credit: Wikipedia)|
So dear biochemicians:
1. Where does the MMPs cleave collagen?
2. How many amino acid residues are there in collagen degradation fragments?
3. Do you think GXXG can mimick collagen fragment?
and dear bioinformaticians:
1. If we consider Collagen I & III into consideration (more relevant for skin) which are the commonest penta and hexa peptide motifs. Do they converge?
|Susan Anton (Photo credit: Wikipedia)|
and finally dear cell biologists:
1. Do all collagen degradation fragments stimulate UVB induced hyaluronic acid degradation as described here: http://www.ncbi.nlm.nih.gov/pubmed/21454612
I have added a wiki page for this to summarise the findings. Feel free to add your thoughts here.
collagen alpha-1(I) chain preproprotein [Homo sapiens] : http://www.ncbi.nlm.nih.gov/protein/NP_000079.2
collagen alpha-2(I) chain precursor [Homo sapiens]
collagen alpha-1(III) chain preproprotein [Homo sapiens]