UDPglucose pyrophosphorylase activity in the diatom Cyclotella cryptica. Pathway of chrysolaminarin biosynthesis

Journal Article · Tue Sep 01 04:00:00 EDT 1987 · J. Phycol.; (United States)

DOI:https://doi.org/10.1111/j.1529-8817.1987.tb02536.x· OSTI ID:5520681

Roessler, P G

UDPglucose pryophosphorylase activity was detected in cell-free extracts of the diatom Cyclotella cryptica T13L Reimann, Lewin and Guillard. When assayed in the direction of UDPglucose formation, the enzyme had maximal activity at pH 7.8 and was stimulated by Mg/sup 2 +/ and Mn/sup 2 +/ ions. 3-Phosphoglycerate and inorganic phosphate had little effect on enzymatic activity, and the enzyme was relatively insensitive to feedback inhibition from UDPglucose. A glucan was formed from UDP-(/sup 14/C)glucose in cell-free extracts of C. cryptica. This glucan had a median molecular weight of 4600 (as determined by gel filtration chromatography) and could be hydrolyzed by laminarinase. Partial acid hydrolysis of the glucan resulted in the formation of glucose and laminaribiose, but not cellobiose. These results suggest that the synthesis of chrysolaminarin (the major storage carbohydrate of diatoms) occurs via the activity of UDPglucose pyrophosphorylase, followed by glucosyl transfer from UDPglucose to the growing ..beta..(1 ..-->.. 3)-linked glucan.

• Research Organization: Solar Energy Research Institute, Golden, CO
• OSTI ID: 5520681
• Journal Information: J. Phycol.; (United States), Journal Name: J. Phycol.; (United States) Vol. 23:3; ISSN JPYLA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ACID HYDROLYSIS
ALDEHYDES
ALGAE
BIOLOGICAL PATHWAYS
BIOSYNTHESIS
CARBOHYDRATES
CARBON 14 COMPOUNDS
CHEMICAL REACTIONS
CHROMATOGRAPHY
DECOMPOSITION
DIATOMS
ENZYME ACTIVITY
ENZYMES
GLUCOSE
HEXOSES
HYDROLYSIS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LYSIS
MOLECULAR WEIGHT
MONOSACCHARIDES
ORGANIC COMPOUNDS
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHOTRANSFERASES
PLANTS
SACCHARIDES
SEPARATION PROCESSES
SOLVOLYSIS
SYNTHESIS
TRACER TECHNIQUES
TRANSFERASES