Cargando…

The Amylases of Insects

Alpha-amylases are major digestive enzymes that act in the first step of maltopolysaccharide digestion. In insects, these enzymes have long been studied for applied as well as purely scientific purposes. In many species, amylases are produced by multiple gene copies. Rare species are devoid of Amy g...

Descripción completa

Detalles Bibliográficos
Autor principal: Da Lage, Jean-Luc
Formato: Online Artículo Texto
Lenguaje:English
Publicado: SAGE Publications 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6176531/
https://www.ncbi.nlm.nih.gov/pubmed/30305796
http://dx.doi.org/10.1177/1179543318804783
_version_ 1783361721396625408
author Da Lage, Jean-Luc
author_facet Da Lage, Jean-Luc
author_sort Da Lage, Jean-Luc
collection PubMed
description Alpha-amylases are major digestive enzymes that act in the first step of maltopolysaccharide digestion. In insects, these enzymes have long been studied for applied as well as purely scientific purposes. In many species, amylases are produced by multiple gene copies. Rare species are devoid of Amy gene. They are predominantly secreted in the midgut but salivary expression is also frequent, with extraoral activity. Enzymological parameters are quite variable among insects, with visible trends according to phylogeny: Coleopteran amylases have acidic optimum activity, whereas dipteran amylases have neutral preference and lepidopteran ones have clear alkaline preference. The enzyme structure shows interesting variations shaped by evolutionary convergences, such as the recurrent loss of a loop involved in substrate handling. Many works have focused on the action of plant amylase inhibitors on pest insect amylases, in the frame of crop protection by transgenesis. It appears that sensitivity or resistance to inhibitors is finely tuned and very specific and that amylases and their inhibitors have coevolved. The multicopy feature of insect amylases appears to allow tissue-specific or stage-specific regulation, but also to broaden enzymological abilities, such as pH range, and to overcome plant inhibitory defenses.
format Online
Article
Text
id pubmed-6176531
institution National Center for Biotechnology Information
language English
publishDate 2018
publisher SAGE Publications
record_format MEDLINE/PubMed
spelling pubmed-61765312018-10-10 The Amylases of Insects Da Lage, Jean-Luc Int J Insect Sci Mini-Review Alpha-amylases are major digestive enzymes that act in the first step of maltopolysaccharide digestion. In insects, these enzymes have long been studied for applied as well as purely scientific purposes. In many species, amylases are produced by multiple gene copies. Rare species are devoid of Amy gene. They are predominantly secreted in the midgut but salivary expression is also frequent, with extraoral activity. Enzymological parameters are quite variable among insects, with visible trends according to phylogeny: Coleopteran amylases have acidic optimum activity, whereas dipteran amylases have neutral preference and lepidopteran ones have clear alkaline preference. The enzyme structure shows interesting variations shaped by evolutionary convergences, such as the recurrent loss of a loop involved in substrate handling. Many works have focused on the action of plant amylase inhibitors on pest insect amylases, in the frame of crop protection by transgenesis. It appears that sensitivity or resistance to inhibitors is finely tuned and very specific and that amylases and their inhibitors have coevolved. The multicopy feature of insect amylases appears to allow tissue-specific or stage-specific regulation, but also to broaden enzymological abilities, such as pH range, and to overcome plant inhibitory defenses. SAGE Publications 2018-10-08 /pmc/articles/PMC6176531/ /pubmed/30305796 http://dx.doi.org/10.1177/1179543318804783 Text en © The Author(s) 2018 http://www.creativecommons.org/licenses/by-nc/4.0/ This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License (http://www.creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage).
spellingShingle Mini-Review
Da Lage, Jean-Luc
The Amylases of Insects
title The Amylases of Insects
title_full The Amylases of Insects
title_fullStr The Amylases of Insects
title_full_unstemmed The Amylases of Insects
title_short The Amylases of Insects
title_sort amylases of insects
topic Mini-Review
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6176531/
https://www.ncbi.nlm.nih.gov/pubmed/30305796
http://dx.doi.org/10.1177/1179543318804783
work_keys_str_mv AT dalagejeanluc theamylasesofinsects
AT dalagejeanluc amylasesofinsects