Transcriptome Analysis and Identification of the Cholesterol Side Chain Cleavage Enzyme BbgCYP11A1 From Bufo bufo gargarizans

Abstract

Bufo bufo gargarizans Cantor are precious medicinal animals in traditional Chinese medicine (TCM). Bufadienolides as the major pharmacological components are generated from the venomous glands of B. bufo gargarizans. Bufadienolides are one type of cardiac aglycone with a six-member lactone ring and have properties of antitumor, cardiotonic, tonsillitis, and anti-inflammatory. The biosynthesis of bufadienolides is complex and unclear. This study explored the transcriptome of three different tissues (skin glands, venom glands, and muscles) of B. bufo gargarizans by high-throughput sequencing. According to the gene tissue–specific expression profile, 389 candidate genes were predicted possibly participating in the bufadienolides biosynthesis pathway. Then, BbgCYP11A1 was identified as a cholesterol side chain cleaving the enzyme in engineering yeast producing cholesterol. Furthermore, the catalytic activity of BbgCYP11A1 was studied with various redox partners. Interestingly, a plant NADPH-cytochrome P450 reductase (CPR) from Anemarrhena asphodeloides showed notably higher production than BbgAdx-2A-BbgAdR from B. bufo gargarizans. These results will provide certainly molecular research to reveal the bufadienolides biosynthesis pathway in B. bufo gargarizans.

The temperature-dependent expression of type II secretion system controls extracellular product secretion and virulence in mesophilic Aeromonas salmonida SRW-OG1

“…They predicted protein structural models corresponding to the five most significant clusters. The confidence of each model was quantitatively measured by the C-score, which was calculated from the importance of thread template alignment and the convergence parameters of the structural assembly simulation ( Li et al., 2022 ). The models were ranked from high C-score to low C-score, and the values were in the range [-5, 2].…”

“…According to the previous description ( Qi et al., 2022 ), the concentration of the bacterial solution from wild type and three mutant strains was adjusted to OD 600 = 0.2, and 1μL of the bacterial suspension was taken to measure the motility of A. salmonicida by the semi-solid agar method. Colony diameters were measured after overnight incubation at 28°C ( Li et al., 2022 ).…”