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Senescence in French‐bean nodules: Occurrence of different proteolytic activities
Author(s) -
Pladys D.,
Rigaud J.
Publication year - 1985
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1985.tb02815.x
Subject(s) - leghemoglobin , proteases , phaseolus , ammonium sulfate precipitation , ammonium , biochemistry , chemistry , nitrogenase , size exclusion chromatography , protease , glycine , alkaline protease , root nodule , proteolytic enzymes , enzyme , chromatography , biology , botany , nitrogen fixation , nitrogen , amino acid , organic chemistry
A decline in nitrogenase activity (C 2 H 2 reduction) of nodules of Phaseolus vulgaris L. cv. Contander was correlated with a decrease in their soluble protein including leghe‐moglobin. Concomitantly, two distinct proteolytic activities against leghemoglobin with acidic and alkaline pH optima were detected. The corresponding proteases were purified about 30‐fold by ammonium sulfate precipitation, gel filtration and hydroxy‐apatite chromatography. Both the acidic (pH optimum 3.5) and the alkaline (pH optimum 8.0) proteases were thiol enzymes. They were characteristic of senescing nodules, whereas only an acidic serine protease was present in functional nodules.