Peptide degradation under ultraviolet light

[Lisa23]

Hello,

i recently read at book at school that said , that ultraviolet light destroys peptides. It didn't tell more about his topic, so i did some research on the internet, but i still don't understand one thing and my teacher wasn't sure about this:

I read certain articles and sometimes the degradation rate of the peptides was more affected by UVA and sometimes by UVB. Why is that? is is because of the different amino acid profiles of the different peptides in regards to at which wavelength the absorb or don't absorb the ultra violet light?

thanks for your help

[BabcockHall]

Do you know which amino acid residues absorb UV light?  That would be how I would start my research into this topic.