Protocol

Analyzing Blood Digestion: Estimation of Active Trypsin Levels in the Mosquito Midgut

  1. Monika Gulia-Nuss1,3
  1. 1Department of Biochemistry and Molecular Biology, Veterinary, and Rangeland Sciences, University of Nevada, Reno, Nevada 89557, USA
  2. 2Department of Agriculture, Veterinary, and Rangeland Sciences, University of Nevada, Reno, Nevada 89557, USA
  1. 3Correspondence: mgulianuss{at}unr.edu

Abstract

The Nα-benzoyl-dl-arginine 4-nitroanilide hydrochloride (BApNA) assay is widely used to quantify trypsin in mosquito midguts and is highly sensitive. BApNA is a chromogenic substrate for proteolytic enzymes such as trypsin and amidase. Hydrolysis of BApNA at the bond between the arginine and the p-nitroaniline moieties releases the chromophore p-nitroaniline, which is detected by colorimetric analysis. The intensity of the color is directly proportional to the amount of trypsin in the solution. Here, we present a trypsin measurement assay specifically using the BApNA substrate.

Footnotes

  • From the Mosquitoes collection, edited by Laura B. Duvall and Benjamin J. Matthews.

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