Hydroxyproline-rich glycoproteins HPRG

Proline is the only protein imino acid. In some proteins, proline is post-translationally hydroxylated to hydroxyproline. Such modifications occur to a large extent in hydroxyproline-rich glycoproteins (HPRG), which are involved in cell wall construction (Moore et al, 1991). Apart from the presence of proline in proteins, this amino acid also occurs in significant concentrations... 

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