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

Jeremiah Reyes; Andrew Nuss; Monika Gulia-Nuss

doi:10.1101/pdb.prot108224

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

Cold Spring Harb Protoc. 2023 Apr 3;2023(4):pdb.prot108224. doi: 10.1101/pdb.prot108224.

Authors

Jeremiah Reyes¹, Andrew Nuss^{1

2}, Monika Gulia-Nuss³

Affiliations

¹ Department of Biochemistry and Molecular Biology, Veterinary, and Rangeland Sciences, University of Nevada, Reno, Nevada 89557, USA.
² Department of Agriculture, Veterinary, and Rangeland Sciences, University of Nevada, Reno, Nevada 89557, USA.
³ Department of Biochemistry and Molecular Biology, Veterinary, and Rangeland Sciences, University of Nevada, Reno, Nevada 89557, USA mgulianuss@unr.edu.

PMID: 36669858
DOI: 10.1101/pdb.prot108224

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.

MeSH terms

Animals
Arginine
Benzoylarginine Nitroanilide
Culicidae* / metabolism
Digestion
Kinetics
Trypsin / chemistry

Substances

Trypsin
4-nitroaniline
Benzoylarginine Nitroanilide
Arginine

Grants and funding

R21 AI139778/AI/NIAID NIH HHS/United States