Growth factors, proteins which specifically enhance the growth of target tissues, were found in the homogenate of submaxillary gland in various molecular forms, due to the association with an esteroproteolytic enzyme. Since it has not been stated if macromolecular complexes were due to a loss of cellular compartmentalization during homogenization, secretory granules were isolated from the gland homogenate and both enzymatic and hormonal activities on the various fractions of granules were determined. The results obtained indicate that growth factors and esteroprotease activity are associated in the same intracellular particles, suggesting a possible role of the enzyme in the maturation of native molecules of growth factors, as described for proinsulin-insulin conversion.
ASJC Scopus subject areas
- Cell Biology