Title of article :
Isolation and characterization of a dual function protein from Allium sativum bulbs which exhibits proteolytic and hemagglutinating activities
Author/Authors :
Parisi، نويسنده , , Mَnica G. and Moreno، نويسنده , , Silvia and Fernلndez-Avilés، نويسنده , , Graciela، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2008
Pages :
11
From page :
403
To page :
413
Abstract :
A dual function protein was isolated from Allium sativum bulbs and was characterized. The protein had a molecular mass of 25–26 kDa under non-reducing conditions, whereas two polypeptide chains of 12.5 ± 0.5 kDa were observed under reducing conditions. E-64 and leupeptin inhibited the proteolytic activity of the protein, which exhibited characteristics similar to cysteine peptidase. The enzyme exhibited substrate specificity and hydrolyzed natural substrates such as α-casein (Km: 23.0 μM), azocasein, haemoglobin and gelatin. It also showed a high affinity for synthetic peptides such as Cbz-Ala-Arg-Arg-OMe-β-Nam (Km: 55.24 μM, kcat: 0.92 s−1). The cysteine peptidase activity showed a remarkable stability after incubation at moderate temperatures (40–50 °C) over a pH range of 5.5–6.5. The N-terminus of the protein displayed a 100% sequence similarity to the sequences of a mannose-binding lectin isolated from garlic bulbs. Moreover, the purified protein was retained in the chromatographic column when Con-A Sepharose affinity chromatography was performed and the protein was able to agglutinate trypsin-treated rabbit red cells. Therefore, our results indicate the presence of an additional cysteine peptidase activity on a lectin previously described.
Keywords :
proteolytic activity , Sativain , Mannose-binding lectin , Hemagglutinating activity , Cysteine peptidase , Allium sativum , Garlic bulbs
Journal title :
Plant Physiology and Biochemistry
Serial Year :
2008
Journal title :
Plant Physiology and Biochemistry
Record number :
2121842
Link To Document :
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