Synonyms: galactinol:sucrose 6-galactosyltransferase
Species: Vicia faba
A raffinose synthase (RFS) was purified 400-fold from maturing seeds of Vicia faba [Lehle73]. The protein was shown to catalyze the transfer of the galactosyl moiety of galactinol to sucrose, leading to the formation of raffinose and myo-inositol. The chemical properties, inhibitors and substrate specificity of the enzyme were determined.
Molecular Weight of Polypeptide: 80 kD (experimental) [Lehle73]
Enzymatic reaction of: raffinose synthase
EC Number: 18.104.22.168galactinol + sucrose → myo-inositol + raffinose
The direction shown, i.e. which substrates are on the left and right sides, is in accordance with the Enzyme Commission system.
The reaction is favored in the direction shown.
In Pathways: stachyose biosynthesisInhibitors (Other): Ag+ [Lehle73], Hg2+ [Lehle73], Zn2+ [Lehle73], Al3+ [Lehle73], Mn2+ [Lehle73]Kinetic Parameters:
T(opt): 42 °C [Lehle73]
pH(opt): 7.0 [Lehle73]
Lehle73: Lehle L, Tanner W (1973). "The function of myo-inositol in the biosynthesis of raffinose. Purification and characterization of galactinol:sucrose 6-galactosyltransferase from Vicia faba seeds." Eur J Biochem 38(1);103-10. PMID: 4774118
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