Differences in the Occurrence and Distribution of Hydroxyproline‐proteins Among the Algae

Fifty algae from seven phyla have been examined in order to determine whether they contain protein‐bound hydroxyproline and whether this hydroxyproline is concentrated in the cell wall. Green algae, with the exception of Nitella , all contain hydroxyproline, and in most cases it is concentrated in the cell wall. Hydroxyproline is also present in low levels in the brown algae, but here it is concentrated in the soluble proteins. Red algae contain no hydroxyproline. The presence of hydroxyproline in blue‐green algae is variable, but when present the levels are low. It appears, then, that the major algal phyla differ with respect to the distribution and occurrence of hydroxyproline‐proteins.