Metabolic Protein Patterns and Monascorubrin Production Revealed through Proteomic Approach forMonascus pilosusTreated with Cycloheximide

Abstract

Monascus species have the unique ability to economically produce many secondary metabolites. However, most metabolic regulation processes in the production of secondary metabolites in Monascus remain unclear. We found that the translational inhibitor cycloheximide induced different expression patterns between the monascorubrin pigment production and the growth in Monascus pilosus. Here, we used the proteomic approach of two-dimensional gel electrophoresis, matrix-assisted laser desorption ionization time-of-flight/time-of-flight liquid chromatography-mass spectrometry (MALDI-TOF/TOF LC-MS), and tandem mass spectrometry (MS/MS) to identify the intracellular and mitochondrial proteins of M. pilosus between the cycloheximide treatment and the control. These results revealed that the cycloheximide-induced down-regulated proteins were involved in transcriptional regulation, peptide synthesis, and other metabolic processes, such as methylation of secondary metabolites. In contrast, the energy-related proteins, such as the transcriptional regulator rosAr and 1,4-alpha-glucan branching enzyme, were up-regulated as compared to the control.

Enhanced Hypolipidemic Effect and Safety of Red Mold Dioscorea Cultured in Deep Ocean Water

“…According to the above, the formation of secondary metabolites is very close to the health function of Monascus -fermented product. Culture conditions or the components added would significantly affect protein expression and levels of the secondary metabolites of Monascus species. − However, production of the functional hypolipidemic ingredients of Monascus -fermented product including monacolin K, monascin, and ankaflavin was increased by supplementation of the special components to stimulate the hypolipidemic effect . Meanwhile, citrinin, known as the mycotoxin involving damage of the liver and kidney, was found in RMR .…”

Profiling the Monascus pilosus Proteome during Nitrogen Limitation

“…This strain was maintained and sporulated on potato dextrose agar (Merck, Darmstadat, Germany) in stock culture. The defined medium for growth of the control group (C/N ratio 20) was glucose nitrate medium containing 3% (w/v) glucose, 0.15% (w/v) NaNO 3 , 0.1% (w/v) MgSO 4 ·7H 2 O, and 0.25% (w/v) KH 2 PO 4 following the method of previous studies . For the nitrogen-limited cultivation treatments with C/N ratios of 30, 40, and 60, the NaNO 3 ingredient used in the medium was modified to 0.1%, 0.075%, and 0.05% (w/v), respectively, while the levels of the other ingredients were kept constant.…”

“…Isoelectric focusing (IEF) was conducted using Amersham Biosciences IPGphor. IPG strips (13 cm; Amersham Biosciences), with a nonlinear pH range from 3 to 10, were used for protein separation by following the protocol described previously (10). The protein pellet was solubilized completely in sample buffer [7 M urea, 2 M thiourea, 4% (w/v) CHAPS, 2% ampholine, 65 mM DTT, with a trace of bromophenol blue].…”

Proteome Response ofMonascus pilosusduring Rice Starch Limitation with Suppression of Monascorubramine Production

“…After centrifugation of the culture broth at 20000g and 4 °C, the cell pellets were stored at -70 °C for further analysis. Preparation of cellular proteins for 2-DE was carried out following procedures detailed elsewhere (15). Briefly, after sonication and disruption with a continuous type presser (Constant Systems Ltd., Northants, England), proteins were extracted in a Tris-HCl buffer.…”