Enzymatic Characterization of a Cubilin-Related Serine Proteinase from the Hard Tick Haemaphysalis longicornis

Journal of Veterinary Medical Science

Takeharu MIYOSHI¹  Naotoshi TSUJI¹  Kozo FUJISAKI²  M. Khyrul ISLAM¹  Tsugihiko KAMIO¹ 

[1] National Institute of Animal Health, National Agricultural Research Organization;National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine

关键词: enzyme activity;    Haemaphysalis longicornis;    serine proteinase;   

DOI  :  10.1292/jvms.66.1195

学科分类：兽医学

来源: Japanese Society of Veterinary Science

【 摘 要 】

References(18)Cited-By(8)In the present study, we performed enzymatic characterization of Haemaphysalis longicornis serine proteinase (HlSP) with a view to shed light on the mechanisms of blood digestion in the hard ticks. Escherichia coli-expressed recombinant HlSP (rHlSP) was shown to potently hydrolyze the synthetic substrates Bz-(DL)-Arg-pNA, Z-Ala-Ala-Leu-pNA and Suc-Ala-Ala-Ala-pNA and yielded an activity of 31.5, 88.2 and 18.3 μmol/min/mg protein, respectively at an optimum temperature of 25°C. However, the enzyme showed little activity to hydrolyze the substratese Suc-Arg-Pro-Phe-His-Leu-Leu-Val-Tyr-MCA and Pyr-Phe-Leu-pNA. The optimum pH for the enzyme was shown to be 4.0 to 5.0. Several inhibitors such as antipain, leupeptin and phenylmethylsulfonyl fluoride (PMSF), specific for serine proteinase were shown to inhibit enzyme activity by 20-82%, while E-64 (specific for cysteine proteinases) and pepstatinA (specific for aspartic proteinases) had shown only little inhibitory effects on it. This is the first report on enzymatic characterization of a functional serine proteinase from the hard ticks.

【 授权许可】

Unknown