Publications by authors named "Marvin-Guy L"
Article Synopsis
- The study focused on improving the production and purification of phage preparations while considering factors like titer, contamination, stability, and cost.
- Peak titers of T4-like coliphages reached 10^9 to 10^10 PFU/ml, and methods like 0.22-μm filtration effectively sterilized phage lysates without losing titer.
- While high-speed centrifugation risked titer loss, alternatives like medium-speed centrifugation and sucrose cushion sedimentation proved effective, and the phages remained stable at room temperature with added magnesium ions.
Article Synopsis
- The DiOGenes study showed that a high-protein/low-glycaemic index (HP/LGI) diet is more effective for weight maintenance after weight loss compared to other diets.
- A proteomic analysis of individuals who successfully maintained weight versus those who regained it identified 18 regulated proteins, with 12 proteins linked to success on the HP diet.
- Two novel biomarkers, pregnancy-zone protein (PZP) and protein S (PROS1), were discovered, indicating biological processes related to fat metabolism and anti-atherogenic effects that support weight maintenance.
Quality control despite mistranslation caused by an ambiguous genetic code.
Proc Natl Acad Sci U S A
October 2008
Article Synopsis
- A high level of accuracy in protein synthesis is crucial for life, and aminoacyl-tRNA synthetases (aaRSs) play a key role in matching amino acids with tRNAs.
- Some aaRSs produce misacylated tRNAs, leading to a mix of inactive mutant proteins and active proteins during translation, which E. coli can tolerate and even depend on for growth.
- E. coli can survive with up to 10% misacylated proteins by initiating a heat shock response that helps misfolded proteins either achieve the correct structure or be broken down, allowing for sufficient functional protein production at a high energy cost.
Article Synopsis
- Early life stress, specifically neonatal maternal deprivation, leads to changes in gut functions in adult rats that resemble symptoms of irritable bowel syndrome (IBS).
- Proteomics analysis revealed that maternal deprivation alters the protein profile in the colonic neuromuscular layer, impacting muscle contractility and stressing the gut's response to future stressors.
- The study identified changes in proteins related to stress response and metabolism, suggesting that early stressors play a significant role in the modulation of gastrointestinal motility and inflammation later in life.
Article Synopsis
- MALDI-TOFMS was used to identify specific markers for the differentiation of T84 colon cancer cells over 28 days, utilizing various measurement techniques.
- Twenty-two ions were identified as diagnostic signals for fully differentiated cells, with ten protein ions proposed as differentiation markers, including ubiquitin.
- Compared to other methods like TER and AP assays, MALDI-MS offers a fast, sensitive, and cost-effective approach for assessing cellular differentiation, making it suitable for high-throughput analysis.
Functional characterization of Pseudomonas fluorescens OprE and OprQ membrane proteins.
Biochem Biophys Res Commun
August 2006
Article Synopsis
- Outer membrane proteins in Pseudomonas, specifically OprD family proteins, help bacteria adjust to different environments by affecting outer membrane permeability.
- Purification and identification of OprE and OprQ porins from P. fluorescens revealed that they form similar ion channels with low conductivity when reconstructed in lipid bilayers.
- Although both proteins have a similar structural pattern, they differ in their amino acid composition and the conditions under which they are overexpressed, showing unique characteristics compared to OprD.
-Omics for prevention: gene, protein and metabolite profiling to better understand individual disposition to disease.
Nestle Nutr Workshop Ser Pediatr Program
May 2006
Article Synopsis
- Heat shock proteins, specifically GroEL or Hsp60 class, are vital for all organisms and have roles in cell attachment and immune modulation beyond their traditional intracellular function.
- Research focused on GroEL protein from the probiotic Lactobacillus johnsonii La1 showed it is present on the bacterial surface and can be detected in culture media.
- The study found that recombinant La1 GroEL can bind to mucins and intestinal cells in a pH-dependent manner and stimulates immune responses, suggesting its potential role in gut health by interacting with mucosal components and affecting pathogenic bacteria like H. pylori.
Article Synopsis
- A comparison of methods for extracting and quantifying proteins from lecithins highlighted hexane-2-propanol-water extraction as the most effective, achieving detection limits of 15 mg/kg and quantification limits of 50 mg/kg.
- Protein recovery rates were high, ranging from 101% to 123%, and varied across different lecithin sources, with standard soy lecithins containing up to 1338 mg/kg of protein.
- Analysis using mass spectrometry identified key proteins in soy and sunflower lecithins, mainly from the 11S globulin fraction, while soy lecithin also contained the allergenic protein P34 from the 7S globulin fraction.
Article Synopsis
- The enteric nervous system (ENS) is a complex part of the peripheral nervous system that operates independently, primarily controlling intestinal movements through the myenteric plexus.
- Researchers used proteomic technology to analyze specific gut tissues from Long Evans rats by dissecting and examining the myenteric plexus-layers from the jejunum, ileum, and colon.
- They identified approximately 80 proteins in each gut segment, with five being specific to each segment, contributing to the first comprehensive protein catalog of the rat intestine's neuromuscular layer, which may help in understanding ENS-related disorders.
Article Synopsis
- LP65 is a newly isolated bacteriophage from industrial meat fermentation, recognized for its ability to infect Lactobacillus plantarum and induce structural changes in the host cell.
- The phage's genome is 131,573 bp long with distinct regions related to DNA replication and structural proteins, showing some similarities to other known phages like Listeria phage A511 and Bacillus phage SPO1.
- Proteomic analysis revealed notable traits of LP65 structural proteins, including a unique change in migration behavior under shear stress, indicating its potential for further research in phage biology.
Article Synopsis
- Whole cells of Bifidobacterium lactis were examined using MALDI-TOFMS, producing consistent mass spectra in the range of 6 to 19 kDa, even after several days of storage at 4°C.
- Fourteen diagnostic ions were identified, with only minor changes observed in the mass signals over time.
- The study successfully distinguished between control and stressed cells (exposed to bile salts) by identifying two control-specific and eight stress-specific ions, highlighting the potential of MALDI-TOFMS for assessing bacterial stress and physiological status.