Evolutionary activation of acidic chitinase in herbivores through the H128R mutation in ruminant livestock.

Placental mammals' ancestors were insectivores, suggesting that modern mammals may have inherited the ability to digest insects. Acidic chitinase (Chia) is a crucial enzyme hydrolyzing significant component of insects' exoskeleton in many species. On the other hand, herbivorous animal groups, such as cattle, have extremely low chitinase activity compared to omnivorous species, e.

Noninsect-Based Diet Leads to Structural and Functional Changes of Acidic Chitinase in Carnivora.

Acidic chitinase (Chia) digests the chitin of insects in the omnivorous stomach and the chitinase activity in carnivorous Chia is significantly lower than that of the omnivorous enzyme. However, mechanistic and evolutionary insights into the functional changes in Chia remain unclear. Here we show that a noninsect-based diet has caused structural and functional changes in Chia during the course of evolution in Carnivora.

Residues of acidic chitinase cause chitinolytic activity degrading chitosan in porcine pepsin preparations.

Commercially available porcine pepsin preparations have been used for the production of chitooligosaccharides with various biomedical activities. However, the origin of this activity is not well understood. Here we show that the chitosan-degrading activity is conferred by residues with chitinolytic activity of truncated forms of acidic chitinase (Chia) persisting in the pepsin preparation.

High expression of acidic chitinase and chitin digestibility in the stomach of common marmoset (Callithrix jacchus), an insectivorous nonhuman primate.

Chitin is a polymer of N-acetyl-D-glucosamine (GlcNAc) and a main constituent of insects' exoskeleton. Insects are rich in protein with high energy conversion efficiency. Recently, we have reported that acidic chitinases (Chia) act as digestive enzymes in mouse, pig and chicken (omnivorous) but not in dog (carnivorous) and bovine (herbivorous), indicating that feeding behavior affects Chia expression levels, and determines chitin digestibility in the particular animals.

Acidic Chitinase-Chitin Complex Is Dissociated in a Competitive Manner by Acetic Acid: Purification of Natural Enzyme for Supplementation Purposes.

Acidic chitinase (Chia) has been implicated in asthma, allergic inflammations, and food processing. We have purified Chia enzymes with striking acid stability and protease resistance from chicken and pig stomach tissues using a chitin column and 8 M urea (urea-Chia). Here, we report that acetic acid is a suitable agent for native Chia purification from the stomach tissues using a chitin column (acetic acid-Chia).

Chitin digestibility is dependent on feeding behaviors, which determine acidic chitinase mRNA levels in mammalian and poultry stomachs.

Chitin, a polymer of N-acetyl-D-glucosamine (GlcNAc), functions as a major structural component in chitin-containing organism including crustaceans, insects and fungi. Recently, we reported that acidic chitinase (Chia) is highly expressed in mouse, chicken and pig stomach tissues and that it can digest chitin in the respective gastrointestinal tracts (GIT). In this study, we focus on major livestock and domestic animals and show that the levels of Chia mRNA in their stomach tissues are governed by the feeding behavior.

Mouse acidic mammalian chitinase exhibits transglycosylation activity at somatic tissue pH.

Mouse acidic mammalian chitinase (AMCase) degrades chitin with highest efficiency at pH 2.0 and is active up to pH 8.0.

Gastric and intestinal proteases resistance of chicken acidic chitinase nominates chitin-containing organisms for alternative whole edible diets for poultry.

Chitin, a polymer of N-acetyl-D-glucosamine (GlcNAc), functions as a major structural component in crustaceans, insects and fungi and is the second most abundant polysaccharide in the nature. Although these chitin-containing organisms have been suggested as novel animal feed resources, chitin has long been considered as indigestible fibers in the animal body. Recently, we reported that acidic chitinase (Chia) is a protease-resistant major glycosidase in mouse gastrointestinal tract (GIT) and that it digests chitin in the mouse stomach.

Acidic mammalian chitinase is a proteases-resistant glycosidase in mouse digestive system.

Chitinases are enzymes that hydrolyze chitin, a polymer of β-1, 4-linked N-acetyl-D-glucosamine (GlcNAc). Chitin has long been considered as a source of dietary fiber that is not digested in the mammalian digestive system. Here, we provide evidence that acidic mammalian chitinase (AMCase) can function as a major digestive enzyme that constitutively degrades chitin substrates and produces (GlcNAc) fragments in the mouse gastrointestinal environment.

Functional Properties of Mouse Chitotriosidase Expressed in the Periplasmic Space of Escherichia coli.

Chitotriosidase (Chit1) is an enzyme associated with various diseases, including Gaucher disease, chronic obstructive pulmonary disease, Alzheimer disease and cystic fibrosis. In this study, we first expressed mouse mature Chit1 fused with V5 and (His)6 tags at the C-terminus (Chit1-V5-His) in the cytoplasm of Escherichia coli and found that most of the expressed protein was insoluble. In contrast, Chit1 tagged with Protein A at the N-terminus and V5-His at the C-terminus, was expressed in the periplasmic space of E.

Loss and Gain of Human Acidic Mammalian Chitinase Activity by Nonsynonymous SNPs.

Acidic mammalian chitinase (AMCase) is implicated in asthma, allergic inflammation, and food processing. Little is known about genetic and evolutional regulation of chitinolytic activity of AMCase. Here, we relate human AMCase polymorphisms to the mouse AMCase, and show that the highly active variants encoded by nonsynonymous single-nucleotide polymorphisms (nsSNPs) are consistent with the mouse AMCase sequence.

Functional properties of the catalytic domain of mouse acidic mammalian chitinase expressed in Escherichia coli.

Mouse acidic mammalian chitinase (AMCase) plays important physiological roles in defense and nutrition. AMCase is composed of an N-terminal catalytic domain (CatD) and a C-terminal chitin-binding domain (CBD). We expressed CatD of mouse AMCase as a recombinant fusion protein with Protein A and V5-His in Escherichia coli (Protein A-CatD-V5-His), evaluated its functional properties and compared them to the full-length AMCase (Protein A-AMCase-V5-His).

Protein A-mouse acidic mammalian chitinase-V5-His expressed in periplasmic space of Escherichia coli possesses chitinase functions comparable to CHO-expressed protein.

Acidic mammalian chitinase (AMCase) has been shown to be associated with asthma in mouse models, allergic inflammation and food processing. Here, we describe an E. coli-expression system that allows for the periplasmic production of active AMCase fused to Protein A at the N-terminus and V5 epitope and (His)6 tag (V5-His) at the C-terminus (Protein A-AMCase-V5-His) in E.