Molecular characterization of a novel aspartyl aminopeptidase that contributes to the increase in glutamic acid content in chicken meat during cooking

Hitomi Yuhara; Akira Ohtani; Mami Matano; Yutaka Kashiwagi; Kenji Maehashi

Food Chemistry: Molecular Sciences (Jul 2021)

Molecular characterization of a novel aspartyl aminopeptidase that contributes to the increase in glutamic acid content in chicken meat during cooking

Hitomi Yuhara,
Akira Ohtani,
Mami Matano,
Yutaka Kashiwagi,
Kenji Maehashi

Affiliations

Hitomi Yuhara: Department of Fermentation Science and Technology, Graduate School of Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
Akira Ohtani: Department of Fermentation Science and Technology, Graduate School of Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
Mami Matano: Department of Fermentation Science, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
Yutaka Kashiwagi: Department of Fermentation Science and Technology, Graduate School of Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan; Department of Fermentation Science, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
Kenji Maehashi: Department of Fermentation Science and Technology, Graduate School of Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan; Department of Fermentation Science, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan; Corresponding author at: Department of Fermentation Science, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan.

Journal volume & issue: Vol. 2
p. 100015

Abstract

Read online

The enzyme involved in the increase in glutamic acid content in chicken meat during cooking was identified and characterized. Chicken homogenate produced significantly more free glutamic acid and exhibited higher glutamyl p-nitroanilide (Glu-pNA) hydrolyzing activity than beef when heat cooked. Amino acid sequencing revealed the presence of aspartyl aminopeptidase (DNPEP) in chicken meat. Using RT-PCR, DNPEP gene expression was detected in chicken breast and thigh muscles, liver, and small intestine, together with various other peptidase genes. Full-length DNPEP cDNA was cloned, and recombinant chicken DNPEP (cDNPEP) was expressed in Escherichia coli. cDNPEP showed five-fold higher activity against Glu-pNA than against aspartyl-pNA, which represents a different substrate specificity than observed for recombinant bovine DNPEP (bDNPEP). The Km values of both DNPEPs with Glu p-NA substrates indicated a higher affinity of cDNPEP for glutamyl residues. This unique substrate specificity of cDNPEP contributes to efficient glutamic acid production in chickens.

Published in Food Chemistry: Molecular Sciences

ISSN: 2666-5662 (Online)
Publisher: Elsevier
Country of publisher: United Kingdom
LCC subjects: Technology: Home economics: Nutrition. Foods and food supply
Website: https://www.journals.elsevier.com/food-chemistry-molecular-sciences

About the journal

Abstract

Keywords