Soluble granule bound

The polymerase can occur in either a soluble (hydrophilic) or a granule-bound (hydrophobic) form, depending on prevailing conditions of life. During growth under carbon substrate limitation, the enzyme exists mainly in the soluble state, and after transfer to nutrient-limiting conditions, e.g., ammonium limitation, the granule-associated polymerase appears (for review see [25]). 

Antibody prepared against SSI effectively neutralized souble SSI activity, but had no effect on either the activities of GBSSI or GBSSII, or even on SSII. Alternatively, antibody prepared against the starch granule-bound proteins effectively inhibited GBSSI activity, but had very little effect on the soluble starch synthases.173... 

Edwards A., Marshall, J., Denyer, K., Sidebottom, C., Visser, R. G., Martin, C., and Smith, A. M. 1996. Evidence that a 77-kilodalton protein from the starch of pea embryos is an isoform of starch synthase that is both soluble and granule-bound. Plant Physiol. 112, 89-97. 

Maddelein, M.-L., Bellanger, F., Deirue, B., Libessart, N., D hulst, C., Van den Koomhuyse, N., Fontaine, T Wieruszeski, J.-M., Decq. A., and Ball, S. 1994a. Genetic dissection of starch metabolism in the monocellular alga Chlamydomonas reinhardtii Determination of granule-bound and soluble starch synthases functions in amylopectin biosynthesis. J. Biol. Chem. 269, 25150-25157. 

Denyer K, Hylton CM, Tenner CF, Smith AM. Identification of 37. multiple isoforms of soluble and granule-bound starch synthase... 

A C. reinhardtii mutant lacking D-enzyme activity has been characterized and has been shown to have significantly lower levels of starch. Other enzymes involved in starch metabolism such as ADP-Glc PPase, granule-bound and soluble starch synthase, BE, phosphorylase, a-glucosidase, amylases, and debranching enzyme activities were not affected. The starch content in the mutant was about 6-13% of wild type and there was an excessive accumulation of maltooligosaccharides up to a polymer size of 16 glucose units. 

Protein/peptide hormones are derived from amino acids. These hormones are preformed and stored for future use in membrane-bound secretory granules. When needed, they are released by exocytosis. Protein/peptide hormones are water soluble, circulate in the blood predominantly in an unbound form, and thus tend to have short half-lives. Because these hormones are unable to cross the cell membranes of their target tissues, they bind to receptors... 

FIGURE 1-7 A lipofiiscin granule from a cortical neuron shows membrane-bound lipid (dense) and a soluble component (gray). The denser component is lamellated. The lamellae appear as paracrystalline arrays of tubular profiles when sectioned transversely (arrow). The granule is surrounded by a single-unit membrane. Free ribosomes also can be seen. X96,000. 

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