Oliva Maria Luiza Vilela, Carmona Adriana K, Andrade Sheila S, Cotrin Simone S, Soares-Costa Andrea, Henrique-Silva Flavio
Department of Biochemistry, Universidade Federal de São Paulo-Escola Paulista de Medicina, Rua Três de Maio, 100, 04044-020 São Paulo, SP, Brazil.
Biochem Biophys Res Commun. 2004 Aug 6;320(4):1082-6. doi: 10.1016/j.bbrc.2004.06.053.
The cDNA of a cystein peptidase inhibitor was isolated from sugarcane and expressed in Escherichia coli. The protein, named canecystatin, has previously been shown to exert antifungal activity on the filamentous fungus Trichoderma reesei. Herein, the inhibitory specificity of canecystatin was further characterized. It inhibits the cysteine peptidases from plant source papain (Ki =3.3nM) and baupain (Ki=2.1x10(-8)M), but no inhibitory effect was observed on ficin or bromelain. Canecystatin also inhibits lysosomal cysteine peptidases such as human cathepsin B (Ki=125nM), cathepsin K (Ki=0.76nM), cathepsin L (Ki=0.6nM), and cathepsin V (Ki=1.0nM), but not the aspartyl peptidase cathepsin D. The activity of serine peptidases such as trypsin, chymotrypsin, pancreatic, and neutrophil elastases, and human plasma kallikrein is not affected by the inhibitor, nor is the activity of the metallopeptidases angiotensin converting enzyme and neutral endopeptidase. This is the first report of inhibitory activity of a sugarcane cystatin on cysteine peptidases.
从甘蔗中分离出一种半胱氨酸蛋白酶抑制剂的cDNA，并在大肠杆菌中表达。该蛋白名为甘蔗半胱氨酸蛋白酶抑制剂，此前已证明其对丝状真菌里氏木霉具有抗真菌活性。在此，进一步表征了甘蔗半胱氨酸蛋白酶抑制剂的抑制特异性。它抑制来自植物源木瓜蛋白酶（Ki = 3.3 nM）和鲍帕因（Ki = 2.1×10⁻⁸ M）的半胱氨酸蛋白酶，但对无花果蛋白酶或菠萝蛋白酶未观察到抑制作用。甘蔗半胱氨酸蛋白酶抑制剂还抑制溶酶体半胱氨酸蛋白酶，如人组织蛋白酶B（Ki = 125 nM）、组织蛋白酶K（Ki = 0.76 nM）、组织蛋白酶L（Ki = 0.6 nM）和组织蛋白酶V（Ki = 1.0 nM），但不抑制天冬氨酸蛋白酶组织蛋白酶D。丝氨酸蛋白酶如胰蛋白酶、胰凝乳蛋白酶、胰蛋白酶和中性粒细胞弹性蛋白酶以及人血浆激肽释放酶的活性不受该抑制剂影响，金属蛋白酶血管紧张素转换酶和中性内肽酶的活性也不受影响。这是关于甘蔗半胱氨酸蛋白酶抑制剂对半胱氨酸蛋白酶抑制活性的首次报道。
