Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Endogenous human milk proteolysis as a function of pH

ABSTRACT: The use of human milk products is increasing for high-risk infants. Human milk contains endogenous enzymes that comprise a dynamic proteolytic system; yet, biological properties of these enzymes and their activities in response to variations including pH within infants are unclear. This study was designed to determine the specificity of enzyme-substrate interactions in human milk as a function of pH.

INSTRUMENT(S):

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Milk

SUBMITTER: Junai Gan

LAB HEAD: J. Bruce German

PROVIDER: PXD012748 | Pride | 2020-05-26

REPOSITORIES: Pride

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
	D0.mgf	Mgf
	D0.mzid.gz	Mzid
	D0.raw	Raw
	D2.mgf	Mgf
	D2.mzid.gz	Mzid

Items per page:

1 - 5 of 106

Publications

Selective Proteolysis of α-Lactalbumin by Endogenous Enzymes of Human Milk at Acidic pH.

Gan Junai J Zheng Jingyuan J Krishnakumar Nithya N Goonatilleke Elisha E Lebrilla Carlito B CB Barile Daniela D German J Bruce JB

Molecular nutrition & food research 20190716 18

<h4>Scope</h4>The use of human milk products is increasing for high-risk infants. Human milk contains endogenous enzymes that comprise a dynamic proteolytic system, yet biological properties of these enzymes and their activities in response to variations including pH within infants are unclear. Human milk has a neutral pH around 7, while infant gastric pH varies from 2 to 6 depending on individual conditions. This study is designed to determine the specificity of enzyme-substrate interactions in ...[more]

PMID: 31271254

Similar Datasets

RNA-sequencing of the human milk fat layer during colostrum, transitional, and mature stages of lactation

Project description:Human milk fat globules, by enveloping cell contents during their secretion into milk, are a rich source of mammary cell RNA. Here, we pair this non-invasive mRNA source with RNA sequencing technology to probe the milk fat layer transcriptome during three stages of lactation: colostral, transitional, and mature milk production. We find that transcriptional profiles cluster not by postpartum day, but by milk Na:K ratio, indicating that women sampled during the same postpartum time frame could be at markedly different stages of gene expression. Each stage of lactation is characterized by a dynamic range (105-fold) in transcript abundances not previously observed with microarray technology. We discovered that transcripts for isoferritins and cathepsins are strikingly abundant during colostrum production, highlighting the potential importance of these proteins for neonatal health. Two transcripts, encoding M-NM-2-casein (CSN2) and a-lactalbumin (LALBA), make up 45% of the total pool of mRNA in mature lactation. Genes significantly expressed across all stages of lactation are associated with making, modifying, transporting, and packaging milk proteins. Stage-specific transcripts are associated with immune defense during the colostral stage, up-regulation of the machinery needed for milk protein synthesis during the transitional stage, and the production of lipids during mature lactation. We observed strong modulation of key genes involved in lactose synthesis and insulin signaling. In particular, PTPRF may serve as a biomarker linking insulin resistance with insufficient milk supply. This study provides the methodology and reference data set to enable future targeted research on the physiological contributors to sub-optimal lactation in humans. Milk fat mRNA profiles were generated from Day 2 and mature milk samples obtained from lactating mothers

2013-07-22 | E-GEOD-45669 | biostudies-arrayexpress

Human milk and gastric peptidomics

Project description:It is unclear to what degree protein degradation occurs in the infant stomach and whether peptides previously annotated for bioactivity are released. This study combined nanospray liquid chromatography separation with time of flight mass spectrometry, comprehensive structural libraries and informatics to interrogate milk of three human mothers and the gastric aspirates from their 4–12 day post-partum infants. Milk from the mothers contained almost two hundred distinct peptides, demonstrating enzymatic degradation of milk proteins beginning either during lactation or between milk collection and feeding. In the gastric samples, 649 milk peptides were identified, demonstrating that digestion continues in the infant stomach. The majority of peptides in both the intact milk and gastric samples were derived from β-casein. The numbers of peptides from β-casein, lactoferrin, α-lactalbumin, lactadherin, κ-casein, serum albumin, bile-salt associated lipase and xanthine dehydrogenase/oxidase were significantly higher in the gastric samples than the milk samples (p<0.05). Six hundred three peptides were significantly different in abundance between milk and gastric samples (p<0.05). Most of the identified peptides have previously identified biological activity. Gastric proteolysis occurs in the term infant in the first two weeks of life releasing biologically active milk peptides with immunomodulatory, antibacterial, and calcium-binding activity of clinical relevance to the proximal intestinal tract.

2014-04-15 | PXD000688 | Pride

Allergen Shedding in Human Milk from Mothers of Preterm Infants: Proteomic and Peptidomic Feasibility and Pilot Analysis

Project description:There is little information regarding the allergen content of milk feeds in the preterm population. Previous studies have evaluated specific proteins/peptides via ELISA, but no studies have performed a broad analysis of the allergenic peptide content and protease activity of milk feeds in this population. Preterm infants spend a critical window of time for immune development in the Newborn Intensive Care Unit (NICU), and may receive fortified donor milk, maternal milk or formula feeds via nasogastric tube or bottle instead of fresh breastmilk via breastfeeding.

2024-01-26 | PXD033473 | Pride

Changes over lactation in breast milk serum proteins.

Project description:The objective of this study is to investigate the changes of the breast milk proteome from four individual mothers over a six month lactation period by shotgun proteomic techniques, because a comprehensive understanding of the human milk proteome may lead to better understanding of the needs of infants. This may contribute to the improvement of infant formula.

2016-02-12 | PXD003465 | Pride

Antibody-independent identification of bovine milk-derived peptides in breast-milk

Project description:Exclusively breast-fed infants can exhibit clear signs of IgE or non IgE-mediated cow’s milk allergy. The definite characterization of dietary cow’s milk proteins (CMP) that survive the maternal digestive tract to be absorbed into the bloodstream and secreted into breast milk remains missing. The aim of this study was to assess the occurrence of CMP-derived peptides in breast milk, using antibody-independent methods. Using high performance liquid chromatography-high resolution mass spectrometry in blinded assays, we identified 11 cow’s milk-derived peptides, including two β-lactoglobulin (2 out 6 samples) and one αs1-casein (1 out 6 samples) fragments, in breast milk from mothers receiving a cup of bovine milk daily. The β-lactoglobulin (β-Lg) fragments, namely f42-54 and f42-57, were absent in milk from mothers who observed a strict dairy-free diet (6 samples). In contrast, neither intact nor hydrolyzed β-Lg was detected by Western blot or competitive ELISA tests. CMP-derived peptides rather than intact CMP may sensitize or elicit allergic responses in the neonate through mother’s milk. Immunologically active peptides from the maternal diet could be involved in priming the newborn’s immune system to drive tolerogenic response in neonates and infants.

2016-07-19 | PXD003657 | Pride

Endegenous human milk peptides

Project description:Variations in endogenous peptide profiles, functionality, and the enzymes responsible for the formation of these peptides in human milk are understudied. Additionally, there is a lack of knowledge regarding peptides in donor human milk, which is used to feed preterm infants when mother’s own milk is not (sufficiently) available. To assess this, 29 human milk samples from the Dutch Human Milk Bank were analyzed as three groups, preterm late lactation stage (LS) (n=12), term early (n=8) and term late LS (n=9). Gestational age (GA) groups were defined as preterm (24-36 weeks) and term (>37 weeks). LS was determined as days postpartum as early (16-36 days) or late (55-88 days). Peptides, analyzed by LC-MS/MS, and parent proteins (proteins from matched peptide sequences) were identified and quantified, after which peptide functionality and the enzymes responsible for protein cleavage were determined. A total of 16 different parent proteins were identified from human milk, with no differences by GA or LS. We identified 1104 endogenous peptides, of which, the majority were from the parent proteins β-casein, polymeric immunoglobulin receptor, αs1-casein, osteopontin, and κ-casein. The absolute number of peptide differed by GA and LS with 30 and 41 differing sequences respectively (p<0.05) Odds likelihood tests determined that 32 peptides had a predicted bioactive functionality, with no significant differences between groups. Enzyme prediction analysis showed that plasmin/trypsin enzymes most likely cleaved the identified human milk peptides. These results explain some of the variation in endogenous peptides in human milk, leading to future targets that may be studied for functionality.

2022-02-24 | PXD007967 | Pride

RNA-Seq data from the milk somatic cell transcriptome of primiparus Assaf dairy sheep

Project description:This research investigates the influence of nutritional protein restriction (NPR) during prepuberty on FE and the milk transcriptome of dairy Assaf ewes during their first lactation. Additionally, it evaluates the differences in the milk transcriptome between lactating ewes with divergent FE using the feed conversion ratio (FCR) and residual feed intake (RFI) indices and assesses milk gene expression as a predictor of FE.

2024-03-01 | E-MTAB-13619 | biostudies-arrayexpress

Changes in Mycobacterium avium subsp. paratuberculosis proteome after cultivation in milk

Project description:Mycobacterium avium subspecies paratuberculosis (MAP) is the causative agent of Johne’s disease in cattle. MAP can be either shed directly into milk by infected cows, or introduced via fecal contamination. Viable MAP are detectable in milk and other dairy products, indicating survival of MAP after the pasteurization process. Although direct evidence is still lacking, MAP are discussed as a possible factor in the morbidity for chronic inflammatory bowel diseases in humans, such as Crohn’s disease and ulcerative colitis. Therefore, it is broadly accepted in the scientific community that exposure to MAP, especially through contaminated milk and dairy products, should be kept to a minimum. To gain deeper insight into the role of milk in MAP transmission and the question of why MAP can survive pasteurization, we investigated MAP proteome changes after incubation in milk at 37°C (simulating the environment in the mammary gland) and 4°C (simulating tank milk) as well as incubation in liquid control medium at 37°C.

2021-08-26 | PXD027444 | Pride

Personalized Human Milk Profiling

Project description:Human milk is the truest form of personalized nutrition, supporting dynamic needs of the infant with important nutritional and bioactive constituents that change throughout lactation. Additionally, human milk is individual specific and is unique for each mother-infant dyad. Proteins and endogenous peptides are 2 key classes of major human milk components making up the proteome, each with unique and synergistic functionality, working to provide protection for the healthy development of infants. Our objective was to comprehensively characterize and quantify the human milk proteome for varying early life challenges. We assessed in-depth individual variations of the human milk proteome across lactation, by mass spectrometry. Finding that the human milk proteome showed continuous and gradual changes over lactation, and that inflammatory events correlated with a strong and rapid change in the composition of human milk proteins and peptides. Personalized human milk profiling resulted in the systematic annotation of the milk proteome, and elucidated how early onset inflammatory events can lead to infant immune training from human milk.

2021-02-09 | PXD014917 | Pride

Peptidomics analysis of milk protein-derived peptides released over time in the preterm infant stomach

Project description:Over the course of milk digestion, native milk proteases and infant digestive proteases fragment intact proteins into peptides with potential bioactivity. This study investigated the release of peptides over three hours of gastric digestion in 14 preterm infant sample sets. The peptide content was extracted and analyzed from milk and gastric samples via Orbitrap tandem mass spectrometry. The relative ion intensity (abundance) and count of peptides in each sample were compared over time and between infants fed milk fortified with bovine milk fortifier and infants fed unfortified milk. Bioactivity of the identified peptides was predicted by sequence homology to known bioactive milk peptides. Both total and bioactive peptide abundance and count continuously increased over three hours of gastric digestion. After accounting for infant weight, length, and post-conceptual age, fortification of milk limited the release of peptides from human milk proteins. Peptides that survived further gastric digestion after their initial release were structurally more similar to bioactive peptides than non-surviving peptides. This work is the first to provide a comprehensive profile of milk peptides released during gastric digestion over time, which is an essential step in determining which peptides are most likely to be biologically relevant in the infant.

2019-03-12 | PXD012192 | Pride

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data