A Purified Aspartic Protease from Akkermansia Muciniphila Plays an Important Role in Degrading Muc2

Abstract

Akkermansia muciniphila can produce various mucin-degrading proteins. However, the functional characteristics of these proteins and their role in mucin degradation are unclear. Of the predicted protein-coding genes, Amuc_1434, which encodes for a hypothetical protein, is the focus in this study. A recombinant enzyme Amuc_1434 containing the 6× His-tag produced in Escherichia coli (hereinafter termed Amuc_1434*) was isolated to homogeneity and biochemically characterised. Results showed that the enzyme can hydrolyse hemoglobin with an activity of 17.21 U/μg. The optimal pH and temperature for hemoglobin hydrolysis of Amuc_1434* were found to be around 8.0 and 40 °C, respectively. Amuc_1434* is identified as a member of the aspartic protease family through the action of inhibitor pepstatin A. Amuc_1434* promotes the adhesion of colon cancer cell line LS174T, which can highly express Muc2. Significantly Amuc_1434* can degrade Muc2 of colon cancer cells. Amuc_1434 is mainly located in the colon of BALB/c mice. These results suggest that the presence of Amuc_1434 from Akkermansia muciniphila may be correlated with the restoration of gut barrier function by decreasing mucus layer thickness.

The Gut-Liver Axis in Cholestatic Liver Diseases

“…Integrity of the mucosal barrier can be disrupted by dysbiosis of the microbiome caused by inflammation, infections, antibiotic usage, western diet, or alcohol consumption [ 41 , 45 , 46 , 47 , 48 , 49 , 50 , 51 ]. The mucus layer interacts with the microbiome and lower abundance of Akkermansia muciniphila was shown to decrease the mucus film [ 52 , 53 , 54 , 55 , 56 , 57 ]. An impaired gut barrier allows microbes and PAMPs to pass and reach the liver via the portal vein [ 34 ].…”

Akkermansia muciniphila Aspartic Protease Amuc_1434* Inhibits Human Colorectal Cancer LS174T Cell Viability via TRAIL-Mediated Apoptosis Pathway

“…Akkermansia muciniphila can use the sugar chain of Muc2 as a carbon source, and degrades it via the Akkermansia-muciniphila-encoded glycosidase [3]. We found that the protease encoded by Akkermansia muciniphila, Amuc_1434*, is the only currently reported protease enzyme able to degrade the Muc2 core protein [4].…”

“…Amuc_1434* protein was produced according to our previous study [4]. BCA (bicinchonininc acid) Protein Assay Kit (C503051) was purchased from Sangon Biotech Co. Ltd. (Shanghai, China).…”

Emerging roles of a pivotal lncRNA SBF2-AS1 in cancers

“…Deficiency in SBF2-AS1 expression regained the sensitivity of gemcitabine-resistant PC cells via repressing cell proliferation, migration, invasion, and EMT [ 27 ]. Both M2 macrophages and exosomes have been shown to be involved in certain phases during progression of tumors or drug resistance [ 62 – 64 ]. One study verified that exosomal lncRNA SBF2-AS1, which is derived from M2 macrophages of pancreatic cancer, regulates the level of X-linked inhibitor of apoptosis protein (XIAP) expression by integrating with miR-122-5p.…”