Dietary Intake and Pneumococcal Vaccine Response Among Children (5-7 Years) in Msambweni Division, Kwale County, Kenya.

Background: Vaccine and sufficient food availability are key factors for reducing pneumonia outbreaks in sub-Saharan Africa. Methods: In this study, the 10-valent pneumococcal conjugate vaccine (Synflorix® or PCV10) was administered to a child cohort (5-7 years old, n = 237) in Msambweni, Kenya, to determine relationships between dietary intake, nutritional/socioeconomic status of mothers/caregivers, and vaccine response. 7-day food frequency questionnaire (FFQ), dietary diversity score (DDS) and single 24-h dietary recall were used to address participants' dietary assessment and nutritional status. Individual food varieties were recorded and divided into 9 food groups as recommended by Food and Agriculture Organization. Anthropometric measurements, nasopharyngeal swabs and vaccine administration were performed at the initial visit. Participants were followed 4-8 weeks with a blood draw for pneumococcal IgG titers assessed by Luminex assay. Findings: Chronic malnutrition was prevalent in the cohort (15% stunting, 16% underweight). Unbalanced dietary intake was observed, with mean energy intake 14% below Recommended Dietary Allowances (1,822 Kcal) for 5-7 years age range. 72% of the daily energy was derived from carbohydrates, 18% from fats and only 10% from proteins. Poor anthropometric status (stunting/underweight) was associated with low socioeconomic/educational status and younger mother/caregiver age (p < 0.002). Limited intake of essential micronutrients (vitamins A, E, K) and minerals (calcium, potassium) associated with low consumption of fresh fruits, vegetables, and animal source foods (dairy, meat) was observed and correlated with poor vaccine response (p < 0.001). In contrast, children who consumed higher amounts of dietary fiber, vitamin B1, zinc, iron, and magnesium had adequate vaccine response (p < 0.05). Correlation between higher dietary diversity score (DDS), higher Vitamin E, K, Zinc intake and adequate vaccine response was also observed (p < 0.03). Interpretation: Overall, this study highlights ongoing food scarcity and malnutrition in Kenya and demonstrates the links between adequate socioeconomic conditions, adequate nutrient intake, and vaccine efficacy.

Human ARMT1 structure and substrate specificity indicates that it is a DUF89 family damage-control phosphatase.

Metabolite damage control is a critical but poorly defined aspect of cellular biochemistry, which likely involves many of the so far functionally uncharacterized protein domain (domains of unknown function; DUFs). We have determined the crystal structure of the human DUF89 protein product of the C6ORF211 gene to 1.85 Å. The crystal structure shows that the protein contains a core α-ß-α fold with an active site-bound metal ion and α-helical bundle N-terminal cap, which are both conserved features of subfamily III DUF89 domains. The biochemical activities of the human protein are conserved with those of a previously characterized budding yeast homolog, where an in vitro phosphatase activity is supported by divalent cations that include Co2+, Ni2+, Mn2+ or Mg2+. Full steady-state kinetics parameters of human DUF89 using a standard PNPP phosphatase assay revealed a six times higher catalytic efficiency in presence of Co2+ compared to Mg2+. The human enzyme targets a number of phosphate substrates similar to the budding yeast homolog, while it lacks a previously indicated methyltransferase activity. The highest activity on substrate was observed with fructose-1-phosphate, a potent glycating agent, and thus human DUF89 phosphatase activity may also play a role in limiting the buildup of phospho-glycan species and their related damaged metabolites.

Spontaneous Isomerization of Long-Lived Proteins Provides a Molecular Mechanism for the Lysosomal Failure Observed in Alzheimer's Disease.

Proteinaceous aggregation is a well-known observable in Alzheimer's disease (AD), but failure and storage of lysosomal bodies within neurons is equally ubiquitous and actually precedes bulk accumulation of extracellular amyloid plaque. In fact, AD shares many similarities with certain lysosomal storage disorders though establishing a biochemical connection has proven difficult. Herein, we demonstrate that isomerization and epimerization, which are spontaneous chemical modifications that occur in long-lived proteins, prevent digestion by the proteases in the lysosome (namely, the cathepsins). For example, isomerization of aspartic acid into l-isoAsp prevents digestion of the N-terminal portion of Aß by cathepsin L, one of the most aggressive lysosomal proteases. Similar results were obtained after examination of various target peptides with a full series of cathepsins, including endo-, amino-, and carboxy-peptidases. In all cases peptide fragments too long for transporter recognition or release from the lysosome persisted after treatment, providing a mechanism for eventual lysosomal storage and bridging the gap between AD and lysosomal storage disorders. Additional experiments with microglial cells confirmed that isomerization disrupts proteolysis in active lysosomes. These results are easily rationalized in terms of protease active sites, which are engineered to precisely orient the peptide backbone and cannot accommodate the backbone shift caused by isoaspartic acid or side chain dislocation resulting from epimerization. Although Aß is known to be isomerized and epimerized in plaques present in AD brains, we further establish that the rates of modification for aspartic acid in positions 1 and 7 are fast and could accrue prior to plaque formation. Spontaneous chemistry can therefore provide modified substrates capable of inducing gradual lysosomal failure, which may play an important role in the cascade of events leading to the disrupted proteostasis, amyloid formation, and tauopathies associated with AD.

Analysis of Glutamine Deamidation: Products, Pathways, and Kinetics.

Spontaneous chemical modifications play an important role in human disease and aging at the molecular level. Deamidation and isomerization are known to be among the most prevalent chemical modifications in long-lived human proteins and are implicated in a growing list of human pathologies, but the relatively minor chemical change associated with these processes has presented a long standing analytical challenge. Although the adoption of high-resolution mass spectrometry has greatly aided the identification of deamidation sites in proteomic studies, isomerization (and the isomeric products of deamidation) remain exceptionally challenging to characterize. Herein, we present a liquid chromatography/mass spectrometry-based approach for rapidly characterizing the isomeric products of Gln deamidation using diagnostic fragments that are abundantly produced and capable of unambiguously identifying both Glu and isoGlu. Importantly, the informative fragment ions are produced through orthogonal fragmentation pathways, thereby enabling the simultaneous detection of both isomeric forms while retaining compatibility with shotgun proteomics. Furthermore, the diagnostic fragments associated with isoGlu pinpoint the location of the modified residue. The utility of this technique is demonstrated by characterizing the isomeric products generated during in vitro aging of a series of glutamine-containing peptides. Sequence-dependent product profiles are obtained, and the abundance of deamidation-linked racemization is examined. Finally, comparisons are made between Gln deamidation, which is relatively poorly understood, and asparagine deamidation, which has been more thoroughly studied.

A Heck-Based Strategy To Generate Anacardic Acids and Related Phenolic Lipids for Isoform-Specific Bioactivity Profiling.

A synthetic strategy for phenolic lipids such as anacardic acid and ginkgolic acid derivatives using an efficient and selective redox-relay Heck reaction followed by a stereoselective olefination is reported. This approach controls both the alkene position and stereochemistry, allowing the synthesis of natural and unnatural unsaturated lipids as single isomers. By this strategy, the activities of different anacardic acid and ginkgolic acid derivatives have been examined in a matrix metalloproteinase inhibition assay.