Invertase biosynthesis

However, pyrimethanil and mepanipyrim do not inhibit proteinase, cellulase or polygalacturnase activity in Botrytis cinerea17 but reduce pectinase and invertase secretion with an associated increase in their intracellular accumulation. This is proposed to be the mechanism of action of the anilinopyrimidines but the biochemical basis of the effect is not known. There is evidence that suggests the involvement of methionine biosynthesis inhibition.18... 

The biosynthesis in yeast of two enzymes that are D-mannoproteins has been studied. A membrane-associated isozyme of invertase (EC 3.2.1.26) has been shown to be a precursor of the external invertase.190 Its molecular weight, as determined by SDS-poly(acrylamide) gel electrophoresis, is 50,000, that is, smaller than that of the external invertase, and it correlates well with the presence of only the inner-core sugars of the final form. It is strictly bound to membranes, possibly those of the endoplasmic reticulum, and it can be completely split191 by endo-/3-N-acetylglucosaminidase H (EC 3.2.1.30). The addition of tunicamycin, which specifically inhibits formation of d-GIcNAc-PP-DoI, inhibits synthesis of external invertase, as well as further formation of the membrane-associated form, which completely disappears after addition of the antibiotic.190 In these aspects, the synthesis of this extracellular enzyme follows the pathway for secreted glycoproteins in animal systems. 

Kim, H. Y., and Suzuki, Y. (1989). Changes in assimilated BC distribution and soluble acid invertase activity of Zinnia elegans induced by Uniconazol an inhibitor of gibberellin biosynthesis. Plant Physiol. 90, 316-321. 

Fig. 6.—Hypothetical Model for the Biosynthesis of Cellulose.184 [Numbers refer to reactions catalyzed by the following enzymes 1, invertase (EC 3.2.1.26) 2, sucrose synthetase 3, hexokinase (EC 2.7.1.1) 4, phosphoglucomutase (EC 2.7.5.1) 5, UDP-glucose pyrophosphorylase and 6, 7, and 8, hypothetical reactions in the pathway to cellulose.]...

Sucrose plays a central role in plant growth and development. Invertase-catalyzed hydrolysis of sucrose is associated with the respiration required for plant growth, whereas sucrose synthase-catalyzed hydrolysis is linked to cell wall or other storage product biosynthesis. Cellulose is synthesized from UDP-glucose using cellulose synthase in membranes. Cellulose protects plant cells from the environment and provides them with a firm structure to access sunlight. 

Conversely, the expression of a yeast derived invertase in potatoes leads to a reduction of these naturally occurring toxicants. The elucidation of the biochemical reason for this reduction (dilution effect due to the increase of the tubers or metabolic interference with the sugar moieties needed for the biosynthesis of the glycoalkaloids) is part of our ongoing research. 

Sucrase (also called saccharase and invertase) hydrolyzes sucrose. In contrast to the abundant information available on the yeast invertase, little is known of the mammalian sucrases. The significance of invertase and lactase in absorption is illustrated by inborn errors of metabolism in which these two enzymes are absent in the intestinal secretion. (The fact that lactase deficiency does not interfere with growth indicates that the galactose needed for biosynthesis of brain lipids or lens proteins can be synthesized endogenously in amounts sufficient to fulfill the metabolic requirements.) In that case, there is an intolerance to lactose or sucrose with no increase in blood glucose levels or without an increase in the levels of disaccharides... 

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