Levoglucosan is the main product derived from pyrolysis of cellulose. A mutant Aspergillus niger CBX-209 could grow on levoglucosan well fermenting it into citric acid with a yield comparable to that on glucose. Levoglucosan hydrolase was absent by measuring glucose formation with the glucose oxidase and peroxidase coupling system. Cell extracts were partly purified by ammonium sulfate fractionation and ion-exchange chromatograph. Direct formation of glucose 6-phosphate from levoglucosan in the presence of ATP and MgCl2 was observed when it was reacted with partly purified enzyme by a combined strategy of enzymological and fast atom bombardment mass spectrometric analysis. These data showed that the mutant used a novel enzyme, levoglucosan kinase, to convert levoglucosan into glucose 6-phosphate. Levoglucosan kinase was an inductive enzyme.
Aspergillus niger ; metabolism ; Enzyme Induction ; Fermentation ; Glucose ; analogs & derivatives ; metabolism ; Glucose-6-Phosphate ; metabolism ; Phosphorylation ; Phosphotransferases ; biosynthesis ; Spectrometry, Mass, Fast Atom Bombardment

Stem cell factor is an important hematopoietic growth factor. In this study, the human stem cell factor was produced by recombinant E. coli, and the structure and biological activity of the recombinant stem cell factor(rhSCF) was studied. It was indicated that the rhSCF was a uncovalent dimer in phosphate buffer,and had the correct mass spectra, mass peptides spectra, composition of amino acid, N-terminal sequernce, C-terminal sequence and intrachain disulfide linkages, rhSCF alone or synergy with rhG-CSF could mobilze hematopoietic progenitors to blood in monkey.
Animals ; Cell Differentiation ; drug effects ; Cells, Cultured ; Chromatography, High Pressure Liquid ; Haplorhini ; Hematopoietic Stem Cells ; cytology ; drug effects ; Humans ; Recombinant Proteins ; chemistry ; genetics ; metabolism ; pharmacology ; Sequence Analysis, Protein ; Spectrometry, Mass, Fast Atom Bombardment ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Stem Cell Factor ; chemistry ; genetics ; metabolism ; pharmacology