TY - JOUR
T1 - Enzymatic description of the anhydrofructose pathway of glycogen degradation. I
T2 - Identification and purification of anhydrofructose dehydratase, ascopyrone tautomerase and a-1,4-glucan lyase in the fungus Anthracobia melanoma
AU - Yu, Shukun
AU - Refdahl, Charlotte
AU - Lundt, Inge
PY - 2004
Y1 - 2004
N2 - The anhydrofructose pathway describes the degradation of glycogen and starch to metabolites via 1,5-anhydro-D-fructose (1,5AnFru). The
enzyme catalyzing the first reaction step of this pathway, i.e., a-1,4-glucan lyase (EC 4.2.1.13), has been purified, cloned and characterized
from fungi and red algae in our laboratory earlier. In the present study, two 1,5AnFru metabolizing enzymes were discovered in the fungus
Anthracobia melaloma for the formation of ascopyrone P (APP), a fungal secondary metabolite exhibiting antibacterial and antioxidant
activity. These are 1,5AnFru dehydratase (AFDH) and ascopyrone tautomerase (APTM). AFDH catalyzed the conversion of 1,5AnFru to
ascopyrone M (APM), a compound that has been earlier presumed to occur biologically, while APTM isomerized the APM formed to APP.
Both enzymes were purified 400-fold by (NH4)2SO4 fractionation, hydrophobic interaction, ion-exchange and gel filtration chromatography.
The purified AFDH showed a molecular mass of 98 kDa on SDS-PAGE and 230 kDa by gel filtration. The corresponding values for APTM
was 60 and 140 kDa. Spectrophotometric and HPLC methods were developed for the assay of these two enzymes. To confirm that A.
melaloma possessed all enzymes needed for conversion of glycogen to APP, an a-1,4-glucan lyase from this fungus was isolated and partially
sequenced. Based on this work, a scheme of the enzymatic description of the anhydrofructose pathway in A. melaloma was proposed.
Keywords: Anhydrofructose pathway; Anthracobia; Ascopyrone; Dehydratase; Glucan lyase; Tautomerase
AB - The anhydrofructose pathway describes the degradation of glycogen and starch to metabolites via 1,5-anhydro-D-fructose (1,5AnFru). The
enzyme catalyzing the first reaction step of this pathway, i.e., a-1,4-glucan lyase (EC 4.2.1.13), has been purified, cloned and characterized
from fungi and red algae in our laboratory earlier. In the present study, two 1,5AnFru metabolizing enzymes were discovered in the fungus
Anthracobia melaloma for the formation of ascopyrone P (APP), a fungal secondary metabolite exhibiting antibacterial and antioxidant
activity. These are 1,5AnFru dehydratase (AFDH) and ascopyrone tautomerase (APTM). AFDH catalyzed the conversion of 1,5AnFru to
ascopyrone M (APM), a compound that has been earlier presumed to occur biologically, while APTM isomerized the APM formed to APP.
Both enzymes were purified 400-fold by (NH4)2SO4 fractionation, hydrophobic interaction, ion-exchange and gel filtration chromatography.
The purified AFDH showed a molecular mass of 98 kDa on SDS-PAGE and 230 kDa by gel filtration. The corresponding values for APTM
was 60 and 140 kDa. Spectrophotometric and HPLC methods were developed for the assay of these two enzymes. To confirm that A.
melaloma possessed all enzymes needed for conversion of glycogen to APP, an a-1,4-glucan lyase from this fungus was isolated and partially
sequenced. Based on this work, a scheme of the enzymatic description of the anhydrofructose pathway in A. melaloma was proposed.
Keywords: Anhydrofructose pathway; Anthracobia; Ascopyrone; Dehydratase; Glucan lyase; Tautomerase
M3 - Journal article
SN - 0304-4165
VL - 1672
SP - 120
EP - 129
JO - BBA General Subjects
JF - BBA General Subjects
ER -