The glucoamylase of Coniophora cerebella

Abstract

1. The major amylolytic enzyme in culture filtrates of Coniophora cerebella grown in starch-containing media has been purified and characterized as a glucoamylase (EC 3.2.1.3). 2. The activity/unit wt. of protein was increased 11-fold and the enzyme showed one major component on polyacrylamide-gel electrophoresis. 3. The glucoamylase had optimum pH4.0-4.5. 4. Hg(2+) completely inhibited the enzyme, but other ions tested had little effect on the activity at the concentration of ions used (5mm). 5. The action of the enzyme on amylopectin, amylose and maltose was studied. Hydrolysis proceeded by the stepwise removal of glucose units from the non-reducing ends of the polymer chains, and the enzyme was able to bypass or to hydrolyse the alpha-(1-->6)-glucosidic linkages at branch points in the amylopectin molecule. Glucose was the only product found in digests of these substrates. 6. At the same substrate concentration (0.1%, w/v) and enzyme concentration, the initial rates of glucose production from amylopectin, amylose and maltose were in the proportions 40:10:1. 7. K(m) values at 40 degrees and pH4.0 were calculated for the enzyme acting on amylopectin, amylose and maltose.

Purification and characterization of three amylases from viscera of hard clam Meretrix lusoria

“…The M of purified amylase AI‐2 was similar to that of tasar silkworm, oyster and human saliva α‐amylases (58, 60, and 55.2 kDa, respectively), 18,31 , 32 tilapia intestine β‐amylase (56.4), 5 small abalone amylase II‐1 (55.7 kDa), 33 and Rhizopus sp. γ‐amylase (58.6 kDa), 34 while that of amylase AI‐1 was similar to those α‐amylases from hog pancreas and Alteromonas haloplanctis (45 and 49.3 kDa, respectively) 32,35 and Clostridium thermosulfurogenes β‐amylases (51 kDa), 4 Coniophora cerebella (48 kDa) and Smucor rouxianus II γ‐amylase (49 kDa) 26,36 . Amylase AII was larger than those of amylases from animal as described above and similar to B. stearothermophilus α‐amylase (115 kDa)., 9 …”

“…6a) were close to those from animal sources: hepatopancreas α‐amylase of Uca minax, Uca pugnax and Uca pugilator 43 (pH 7.3), α‐amylases from human saliva, liver and pancreas, 32 (pH 6.9) and hog, dog, ostrich and chicken pancreas 6,32 , 44,45 (pH 6.9, 6.9, 7.5 and 7.5, respectively) and oyster amylase 18 (pH 7.0). However, the optimal pH of γ‐amylases from Coniophora cerebella 26 (pH 4.0–4.5) , Rhizopus species 34 (pH 4.5–5.0) , A. niger 37 (pH 4.5–5.0) and Aspergillus awamori 28 (pH < 4.5) were found to be lower than those of purified amylases.…”

“…According to our previous study, 33 Cu 2+ almost completely inhibited the small abalone amylases II‐1 and II‐2 and amylases A‐1, AI‐2 and AII from hard clam were also completely inhibited by Cu 2+ . However, it did not inhibit γ‐amylases of A. awamori 28 and Coniophora cerebella 26 . Properties, such as Ca 2+ ‐binding ability of α‐amylase vary with the sources 52–54 .…”

“…In general, the M of a -, band g -amylases were 42-115, 31.6-215 and 48-86 kDa, respectively. 5,[23][24][25][26][27][28][29][30] The M of purified amylase AI-2 was similar to that of tasar silkworm, oyster and human saliva a -amylases (58, 60, and 55.2 kDa, respectively), 18,31,32 tilapia intestine b -amylase (56.4), 5 small abalone amylase II-1 (55.7 kDa), 33 and Rhizopus sp. g -amylase (58.6 kDa), 34 while that of amylase AI-1 was similar to those a -amylases from hog pancreas and Alteromonas haloplanctis (45 and 49.3 kDa, .0 † One unit of amylase activity is defined as the amount of reducing sugar that gives an increase of the absorbance at 490 nm by 1 after 10 min incubation at 37.5 ∞ C (using soluble starch as substrate).…”

Soil Enzyme: The State-of-Art

“…It is known to be constituted by amylase and amylase (Pazur 1965;King 1967;Thoma et al 1971). Studies have shown that amylases are synthesized by plants, animals, and micro-organisms, whereas amylase is mainly synthesized by plants (Pazur 1965;Thoma et al 1971).…”