Mung bean seedlings, enzyme from

Particulate enzyme fractions from mung bean seedlings and from cotton bolls were found to incorporate " C-glucose from UDP-[U- C]-Glc into an alkali-insoluble polymer that was probably cellulose [105,106]. A cell-free extract ob-... 

Conversion of the a-D-glucopyranosyl derivative (94a) into the a-D-galactopyranosyl ester (95a) was demonstrated370 in 1951 as the first example of an enzymic reaction of a sugar nucleotide. The enzyme that catalyzes this reaction, namely, uridine 5 -(a-D-glu-copyranosyl pyrophosphate) 4"-epimerase,371 is common in Nature. Purified preparations have been obtained from yeast,372 373 Escherichia coli 374-376 mung-bean seedlings,377 wheat germ,378 and animal tissues.244,379 380... 

The interaction of F with Ca has been widely known. Many enzymes that occur in different plant tissues have been shown to require Ca for activity. Examples include amylase (Yu 1986) and invertase (Yu 1997 Ouchi et al. 1999) from germinating mung bean seedlings. 

Further support for the operation of the shikimate pathway in higher plants has been provided by studies on enzymes isolated and characterised from plant sources. DAMP synthetase activity has thus been demonstrated in extracts of several plant tissues. An enzyme preparation was also obtained from sweet potato which catalysed the formation of DAHP from D-erythrose-4-phosphate (7) and phosphoenolpyruvate (8) and had properties very similar to those enzymes isolated from bacterial sources. Nandy and Ganguli have similarly demonstrated the presence of DAHP synthetase activity in mung bean Phaseolus aureus) by showing that extracts of mung bean seedlings converted a mixture of the two substrates (7 and 8) to 3-dehydroshikimate (11). 

An enzyme similar to the 3 -nucleotidase of mung bean has been isolated from germinating wheat seedlings and purified 800-fold (90). The preparation possessed DNase, RNase, and 3 -nucleotidase activities. These three activities were similar in pH optima, requirements for Zn2+ and sulfhydryl compounds, stability to storage, temperature inactivation... 

The conversion of D-mannose 6-phosphate into D-mannosyl phosphate is catalyzed by phosphomannomutase, an enzyme distinct from phosphoglucomutase. Both enzymes have been detected by Mathe-son705 in cassia seeds, mung beans, orchid tubers, and pea seedlings. These enzymes from cassia seeds have been separated from one another by chromatography on DEAE- and O-phosphono-cellulose columns, and further characterized. Phosphomannomutase from animal sources requires the presence of either D-galactose 1,6-bisphosphate or D-mannose 1,6-bisphosphate for activity.708 D-Mannosyl phosphate may then be enzymically transformed into GDP-D-mannose in the... 

Metal requirements for the plant enzyme closely resemble those of the microbial enzyme which require a divalent cation such as Mn for full activity. Thus, Mn " and Co activated the synthase from pea seedlings and cauliflower florets (Rothe et al., 1976 Huisman and Kosuge, 1974) but Mg " " was the most effective activator for the mung bean enzyme (Minamikawa, 1967 Minamikawa and Uritani, 1967). Three multiple forms of the enzyme were detected in pea seedlings but little is known about their intracellular... 

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