کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2436546 1553738 2006 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Identification and characterisation of a leucine aminopeptidase from the hard tick Haemaphysalis longicornis
موضوعات مرتبط
علوم زیستی و بیوفناوری ایمنی شناسی و میکروب شناسی انگل شناسی
پیش نمایش صفحه اول مقاله
Identification and characterisation of a leucine aminopeptidase from the hard tick Haemaphysalis longicornis
چکیده انگلیسی

Aminopeptidases responsible for blood digestion have yet to be identified in haematophagous ticks. We report here the cloning and molecular characterisation of a cDNA encoding leucine aminopeptidase, a member of the M17 cytosolic aminopeptidase family, from the hard tick Haemaphysalis longicornis (HlLAP). Endogenous HlLAP was detected in the soluble fraction of adult tick extracts by immunoblotting. Immunohistochemical studies demonstrated that endogenous HlLAP expression mainly took place in the cytosol of midgut epithelial cells. Furthermore, expression of HlLAP was induced by a blood-feeding process. A functional recombinant HlLAP expressed in Escherichia coli efficiently hydrolyses synthetic substrates for aminopeptidase, a leucyl (with the Km value 0.19 ± 0.011 mM and Vmax value 157.2 ± 3.17 nmol/min/mg protein) and a methionyl substrate (with the Km value 0.12 ± 0.0052 mM and Vmax value 171.9 ± 2.31 nmol/min/mg protein). Enzyme activity was found to be optimum at pH 8 and 35 °C. The recombinant HlLAP enzyme activity was strongly dependent on metal divalent cations, Mn2+, and was inhibited by bestatin. These results indicate that HlLAP play an important role for host’s blood digestion process.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal for Parasitology - Volume 36, Issues 10–11, September 2006, Pages 1123–1132
نویسندگان
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