Does Cellulose Have a Protein Component?

During our investigation of the minor constituents of cellulose from cotton fibers, samples were subjected to repeated hydrolysis in 6N HCl. In addition to monosaccharides, several oligosaccharides were also released.  Investigation of the oligosaccharides suggested that they may have a peptide component since amino acids were found in the hydrolyzates.  Several isolated oligosaccharide fractions were found to contain protein by the Lowry assay as did the 6N HCl hydrolyzate.  The oligosaccharide fractions contain s-inositol, sorbitol, galactose, glucose and mannose as well as several amino acids. Since these fractions are isolated from a 6N HCl hydrolyzate, if a protein were present, it is probable that only a small portion would not be  degraded.  Light microscopy of the particulate material in the 6N HCl hydrolyzate shows  an apparent relative increase in crystalline material following treatment with chymotrypsin and proteinase K but not following treatment with trypsin. Such apparent differences in structure  may be due to  differential exposure of   cellulose  through selective removal of protein by the different protolytic enzymes. The particulate material does not stain readily with Coomassie blue; however, treatment with sodium metaperiodate changes the morphology of the particles and facilitates staining with Coomassie blue.  These results suggest that there may be a protein   component  within cellulose.   Cellulose is synthesized in close association with microtubules.  Protein primers have been demonstrated for glycogen and starch. These findings suggest  a possible protein component  embedded in  cellulose.