Purification and properties of pi-repressible acid phosphatases from Aspergillus nidulans

Control of Acid Phosphatases Expression from Aspergillus niger by Soil Characteristics

“…The MichaelisMenten constant (Km) was 0.31 mM with V max = 147.06 U mg -1 mycelium for the eAPase, showing a relatively high specificity to the substrate when compared with eAPase 0.57 mM with V max = 14,285.71 U mg -1 mycelium. Similar values of Km for the extracellular acid phosphatases as 0.38-0.53 mM were found for A. nidulans (Nozawa et al 1998). However, higher values of Km as 0.95 and 1.3mM were calculated for the acid phosphatases of A. niger (Gargova et al 2006) and Humicola lutea (Micheva-Viteva et al 2000), respectively.…”

The Aspergillus nidulans pyrG89 Mutation Alters Glycosylation of Secreted Acid Phosphatase

“…Secreted acid phosphatase from A. nidulans grown at pH 5.0 was purified to apparent homogeneity by SDS-PAGE as previously described (Nozawa et al, 1998). To assay phosphatase activity the buffers used to cover the pH range required were 0.1 M citric acid/NaOH (pH 4.0 -6.0) (Nozawa et al, 1995), 0.1 M maleic acid/NaOH (pH 6.0 -7.5), and 0.1 M Tris-HCl (pH 7.5-8.0).…”

“…nidulans at pH 5.0. (A) Samples containing about 0.5 units of the enzymes were separated by electrophoresis and the enzyme activity bands were developed using ␣-naphthyl phosphate as the substrate, pH 6.0, without prior incubation of the slab gels with any buffer (Nozawa et al, 1998) Fig. 3) secreted by A. nidulans.…”

“…3, Table 1). We have recently shown that both forms I and II (and probably form III) of the acid phosphatase secreted by A. nidulans are encoded by the structural gene pacA (Nozawa et al, 1998). Thus, these isozymes may be generated by different patterns of glycosylation and other posttranslational modifications of the protein.…”

“…Thus, these isozymes may be generated by different patterns of glycosylation and other posttranslational modifications of the protein. The mature secreted protein molecules may not be homogeneously processed and released into the culture medium (Nozawa et al, 1998). In addition, the major acid phosphatase II-like activity (Fig.…”