Multicopper Oxidase from Lactobacillus hilgardii: Mechanism of Degradation of Tyramine and Phenylethylamine in Fermented Food.

Elevated levels of biogenic amines (BAs) in fermented food can have negative effects on both the flavor and health. Mining enzymes that degrade BAs is an effective strategy for controlling their content. The study screened a strain of Lactobacillus hilgardii 1614 from fermented food system that can degrade BAs. The multiple copper oxidase genes LHMCO1614 were successfully mined after the whole genome protein sequences of homologous strains were clustered and followed by homology modeling. The enzyme molecules can interact with BAs to stabilize composite structures for catalytic degradation, as shown by molecular docking results. Ingeniously, the kinetic data showed that purified LHMCO1614 was less sensitive to the substrate inhibition of tyramine and phenylethylamine. The degradation rates of tyramine and phenylethylamine in huangjiu (18% vol) after adding LHMCO1614 were 41.35 and 40.21%, respectively. Furthermore, LHMCO1614 demonstrated universality in degrading tyramine and phenylethylamine present in other fermented foods as well. HS-SPME-GC-MS analysis revealed that, except for aldehydes, the addition of enzyme treatment did not significantly alter the levels of major flavor compounds in enzymatically treated fermented foods (p > 0.05). This study presents an enzymatic approach for regulating tyramine and phenylethylamine levels in fermented foods with potential applications both targeted and universal.

The tissue expression levels of SUMO1P 3 may be a reliable prognostic biomarker to predict the clinical outcomes in patients with HCC.

Small ubiquitin-like modifier 1 pseudogene 3 (SUMO1P3) is a novel identified long non-coding RNA that is upregulated in several cancers and exerts its oncogenic effects via multiple pathways. SUMO1P3 was significantly higher in HCC tissues and cells than in non-cancerous specimens and normal cells. SUMO1P3 knockdown inhibited the proliferation, migration, and invasion of HCC cells. In the present study, we investigated the clinical significance and prognostic value of SUMO1P3 in HCC.A total of 123 patients were pathologically diagnosed as primary HCC and underwent surgical resection at the Department of Hepatopancreatobiliary Surgery, The Second Affiliated Hospital of Kunming Medical University from March 2014 to November 2019. The expression differences between HCC tissues and matched normal tissues were analyzed using paired Student's t test. Chi-squared test was used for correlation analysis. Survival curves were plotted using the Kaplan-Meier method and were compared via the log-rank test. The independent prognostic value of SUMO1P3 expression was evaluated using results from univariate and multivariate Cox regression models.As revealed by quantitative RT-PCR analysis, SUMO1P 3 expression level was significantly higher in HCC cancer tissues compared with normal adjacent tissues (mean ±â€ŠSD: 4.341 ±â€Š1.320 vs 1.000 ±â€Š0.3666, P < .001). The χ test showed that the SUMO1P 3 expression level was significantly associated with tumor size (P = .031), capsular invasion (P = .011), vascular invasion (P = .004), Edmondson-Steiner grade (P = .002), and TNM stage (P = .001). The patients with high SUMO1P 3 expression showed shorter 5-year overall survival than those with low SUMO1P 3 expression (P = .034; log-rank test). Multivariate regression analysis showed that the status of SUMO1P 3 expression was an independent prognostic factor for overall survival (HR = 2.107, 95% CI: 1.478-9.014, P = .031).The expression levels of SUMO1P 3 may be a reliable prognostic biomarker to predict the clinical outcomes in patients with HCC.