Chlamydomonas Agglutinin is a Hydroxyproline-Rich Glycoprotein

The mt⁺ sexual agglutinin from Chlamydomonas reinhardi is shown to contain ≈12% hydroxyproline, and two inhibitors of hydroxyproline formation, α,α‧-dipyridyl and 3,4-dehydroproline, are shown to block the production of agglutinin activity in an in vivo bioassay system. These results indicate that the agglutinin glycoprotein may be related to a class of hydroxyproline-rich glycoproteins found in the extracellular matrix of higher plants, several of which have been shown to have lectin activity.