The biosynthesis of sucrose phosphate.
نویسندگان
چکیده
The enzymic formation of sucrose from UDPGl and fructose has been described in the preceding paper (1). While some preparations of the enzyme were found to be almost devoid of action of fructose-6-phosphate, other extracts catalyzed the formation of free sucrose either from fructose or from its phosphate. Since these extracts contain phosphatase, it seemed likely that the action on fructose phosphate was the sum of Reaction 1 plus Reaction 2.
منابع مشابه
Role and Regulation of Sucrose-phosphate Synthase in Higher Plants.
Sucrose-phosphate synthase (SPS; E.C. 2.4.1.14) is the plant enzyme thought to play a major role in sucrose biosynthesis. In photosynthetic and nonphotosynthetic tissues, SPS is regulated by metabolites and by reversible protein phosphorylation. In leaves, phosphorylation modulates SPS activity in response to light/dark signals and end-product accumulation. SPS is phosphorylated on multiple ser...
متن کاملThe biosynthesis of sucrose.
The enzyme, which was named sucrose phosphorylase, has not been found in plant tissues (4), and thus the mechanism of sucrose synthesis remains obscure. Evidence obtained from tracer experiments led Buchanan et al. (5, 6) to assume that in plants sucrose phosphate is formed from UDPG’ and fructose-l-phosphate. This hypothesis stimulated work which led to the discovery of an enzyme which catalyz...
متن کاملThe Biosynthesis of Sucrose and Nucleoside Diphosphate Glucoses in Phaseolus aureus.
Sucrose-phosphate synthetase is detectable only in intact chloroplast preparations of Phaseolus aureus. In contrast, sucrose synthetase and uridine diphosphate glucose (UDP-glucose) pyrophosphorylase activities are low in extracts of photosynthetic tissues of P. aureus but are high in extracts of nonphotosynthetic tissues. Activities for ADP-, dTDP-, CDP-, and GDP-glucose pyrophosphorylases are...
متن کاملChanges in Starch Formation and Activities of Sucrose Phosphate Synthase and Cytoplasmic Fructose-1,6-bisphosphatase in Response to Source-Sink Alterations.
Short term experiments were conducted with vegetative soybean plants (Glycine max L. Merr. ;Ransom' or ;Arksoy') to determine whether sourcesink manipulations, which rapidly changed the ;demand' for sucrose and partitioning of photosynthetically fixed carbon into starch, were associated with alterations in activities of sucrose-P synthase and/or cytoplasmic fructose-1,6-bisphosphatase in leaf e...
متن کاملGlycogen biosynthesis via UDP-glucose in the ruminal bacterium Prevotella bryantii B1(4).
Prevotella bryantii is an important amylolytic bacterium in the rumen that produces considerable amounts of glycogen when it is grown on maltose. Radiolabel studies indicated that glucose-1-phosphate was converted to UDP-glucose, and this latter intermediate served as the immediate precursor for glycogen synthesis. High levels of UDP-glucose pyrophosphorylase activities (> 1,492 nmol/min/mg of ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- The Journal of biological chemistry
دوره 214 1 شماره
صفحات -
تاریخ انتشار 1955