... Quaternary structure of protein is an association when new biological properties appear which are unusual in tertiary structure. ... Catalytic activity was determined by spectrophotometric method with the use of rhodamine 6G, amount of protein was assayed by Lawry method. ... This method allows to obtain an image of immobilized on mica lipase surface, and this permits to conclude an important role of quaternary structure in lipase catalytic activity regulation. abstract (PDF) . ...