Differential Protein Expression in Exponential and Stationary Growth Phases of Mycobacterium avium subsp. hominissuis 104

Mycobacterium avium complex (MAC) is the most common non-tuberculous mycobacterium (NTM) and causes different types of pulmonary diseases. While genomic and transcriptomic analysis of Mycobacterium avium 104 (M. avium 104) has been extensive, little is known about the proteomics of M. avium 104. We utilized proteomics technology to analyze the changes in the whole proteome of M. avium 104 during exponential and stationary growth phases. We found 12 dys-regulated proteins; the up-regulated protein hits in the stationary phase were involved in aminopeptidase, choline dehydrogenase, oxidoreductase, and ATP binding, while the down-regulated proteins in the stationary phase were acetyl-CoA acetyltransferase, universal stress protein, catalase peroxidase, and elongation factor (Tu). The differently expressed proteins between exponential and stationary phases were implicated in metabolism and stress response, pointing to the functional adaptation of the cells to the environment. Proteomic analysis in different growth phases could participate in understanding the course of infection, the mechanisms of virulence, the means of survival, and the possible targets for treatment.

Mapping choline metabolites in normal and transformed cells

Introduction Choline is an essential human nutrient that is particular important for proliferating cells, and altered choline metabolism has been associated with cancer transformation. Yet, the various metabolic fates of choline in proliferating cells have not been investigated systematically. Objectives This study aims to map the metabolic products of choline in normal and cancerous proliferating cells. Methods We performed 13C-choline tracing followed by liquid chromatography-high resolution mass spectrometry (LC-HRMS) analysis of metabolic products in normal and in vitro-transformed (tumor-forming) epithelial cells, and also in tumor-derived cancer cell lines. Selected metabolites were quantified by internal standards. Results Untargeted analysis revealed 121 LCMS peaks that were 13C-labeled from choline, including various phospholipid species, but also previously unknown products such as monomethyl- and dimethyl-ethanolamines. Interestingly, we observed formation of betaine from choline specifically in tumor-derived cells. Expression of choline dehydrogenase (CHDH), which catalyzes the first step of betaine synthesis, correlated with betaine synthesis across the cell lines studied. RNAi silencing of CHDH did not affect cell proliferation, although we observed an increased fraction of G2M phase cells with some RNAi sequences, suggesting that CHDH and its product betaine may play a role in cell cycle progression. Betaine cell concentration was around 10 µM, arguing against an osmotic function, and was not used as a methyl donor. The function of betaine in these tumor-derived cells is presently unknown. Conclusion This study identifies novel metabolites of choline in cancer and normal cell lines, and reveals altered choline metabolism in cancer cells.

Differential Protein Expression in Exponential and Stationary Growth Phases of Mycobacterium avium subsp. hominissuis 104

Background:Mycobacterium avium complex (MAC) is the most common non-tuberculous mycobacteria (NTM) causing different types of pulmonary diseases. Although, genomic and transcriptomic analysis of Mycobacterium avium 104 (M. avium 104) have extensively done, little is known about the proteomics of M. avium 104. Methods:We utilized the proteomics technology to analyze the changes in the whole proteome of M. avium 104 during exponential and stationary growth phases. Results:We found 12 dys-regulated proteins; the up-regulated protein hits in the stationary phase were involved in aminopeptidase, choline dehydrogenase, oxidoreductase, and ATP binding, while, the down-regulated proteins in the stationary phase were acetyl-CoA acetyltransferase, universal stress protein, catalase peroxidase, and elongation factor (Tu). The differently expressed proteins between exponential and stationary phases were implicated in metabolism and stress response pointing to the functional adaptation of the cells to the environment. Conclusion:Proteomic analysis in different growth phases could participate in understanding the course of infection, the mechanisms of virulence, the means of survival, and the possible targets for treatment.

BETAINE SUPPLEMENTATION FOR VARIOUS CLINICAL DISORDERS

Betaine is distributed widely in animals, plants, and microorganisms and rich dietary sources include seafood, especially marine invertebrates. Betaine is N-trimethylated amino acid called as glycine betaine. It is a by-product. Betaine aldehyde is produced when choline dehydrogenase acts on choline, then betaine aldehyde is oxidized to form betaine by aldehyde dehydrogenase. Metabolic derived betaines possess various functions in our body in which they act as methyl donor which helps in liver function, detoxication, and cellular functions. It plays an important role in fat metabolism. Recent research found that betaine can convert homocysteine to cysteine thus they prevent heart disease. Choline is oxidized to betaine in liver and kidney. Intracellular betaine serves as an osmolyte that regulates cell volume and tissue integrity. Betaine not only plays as an osmolyte but also play a major role in the protection of the liver and other tissues. Consequently, it has been proposed that betaine has significant nutrient for prevention of chronic disease. Betaine has been shown to protect internal organs, improve vascular risk factors, and enhance performance. Databases of betaine content in food are being developed for correlation with population health studies. This review focuses on the aspects of wide research field with emphasis on a recent data relevant to various human diseases.

Structural and functional analysis of betaine aldehyde dehydrogenase fromStaphylococcus aureus

When exposed to high osmolarity, methicillin-resistantStaphylococcus aureus(MRSA) restores its growth and establishes a new steady state by accumulating the osmoprotectant metabolite betaine. Effective osmoregulation has also been implicated in the acquirement of a profound antibiotic resistance by MRSA. Betaine can be obtained from the bacterial habitat or produced intracellularly from cholineviathe toxic betaine aldehyde (BA) employing the choline dehydrogenase and betaine aldehyde dehydrogenase (BADH) enzymes. Here, it is shown that the putative betaine aldehyde dehydrogenase SACOL2628 from the early MRSA isolate COL (SaBADH) utilizes betaine aldehyde as the primary substrate and nicotinamide adenine dinucleotide (NAD+) as the cofactor. Surface plasmon resonance experiments revealed that the affinity of NAD+, NADH and BA forSaBADH is affected by temperature, pH and buffer composition. Five crystal structures of the wild type and three structures of the Gly234Ser mutant ofSaBADH in the apo and holo forms provide details of the molecular mechanisms of activity and substrate specificity/inhibition of this enzyme.