粗糙脉孢菌的pho-2A突变体缺乏磷酸根可阻遏的碱性磷酸酶（EC 3.1.3.1），在磷酸根可阻遏的酸性磷酸酶（EC 3.1.3.2）方面也存在缺陷。

The pho-2A mutant of Neurospora crassa which is deficient in Pi-repressible alkaline phosphatase (EC 3.1.3.1) is also defective in Pi-repressible acid phosphatase (EC 3.1.3.2).

Han S W, Maccheroni W, Rossi A

Departamento de Bioquímica e Microbiologia, Universidade Estadual Paulista, Rio Claro, Brasil.

Braz J Med Biol Res. 1992;25(5):441-7.

Abstract

The mycelial Pi-repressible acid phosphatase presented p-nitrophenylphosphatase activity with negative cooperativity and Michaelian behavior when synthesized by the wild-type and pho-2A mutant strains of Neurospora crassa, respectively. 2. The major acid phosphatase present in cell extracts of the pho-2A mutant of N. crassa grown in low Pi medium is more thermolabile (t1/2 = 4 min at 54 degrees C, pH 5.4) than that of the wild strain (stable for at least 80 min at 54 degrees C, pH 5.4). 3. The pho-2A mutant of N. crassa secreted a more thermolabile acid phosphatase (t1/2 = 30 min at 50 degrees C, pH 5.4) than the wild strain (t1/2 of at least 80 min at 50 degrees C, pH 5.4). 4. The pho-2A mutant of N. crassa synthesized a more thermolabile acid phosphatase (t1/2 = 37 min at 54 degrees C, pH 5.4) than the wild strain in high Pi medium (t1/2 = 14 min at 54 degrees C, pH 5.4). 5. The pleiotropic nature of the pho-2 locus and its possible involvement in the mechanism of phosphatase secretion by N. crassa are proposed.

摘要

当粗糙脉孢菌的野生型和pho - 2A突变株分别合成丝状菌Pi抑制性酸性磷酸酶时，其对硝基苯磷酸酶活性呈现负协同性和米氏行为。2. 在低磷培养基中生长的粗糙脉孢菌pho - 2A突变体的细胞提取物中存在的主要酸性磷酸酶比野生菌株的更不耐热（在54℃、pH 5.4时t1/2 = 4分钟）（在54℃、pH 5.4时至少稳定80分钟）。3. 粗糙脉孢菌的pho - 2A突变体分泌的酸性磷酸酶比野生菌株更不耐热（在50℃、pH 5.4时t1/2 = 30分钟）（在50℃、pH 5.4时t1/2至少为80分钟）。4. 在高磷培养基中，粗糙脉孢菌的pho - 2A突变体合成的酸性磷酸酶比野生菌株更不耐热（在54℃、pH 5.4时t1/2 = 37分钟）（在54℃、pH 5.4时t1/2 = 14分钟）。5. 提出了pho - 2基因座的多效性及其可能参与粗糙脉孢菌磷酸酶分泌机制的观点。