Human Milk Proteins

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Bo Lönnerdal - One of the best experts on this subject based on the ideXlab platform.

  • bioactive peptides derived from Human Milk Proteins an update
    Current Opinion in Clinical Nutrition and Metabolic Care, 2020
    Co-Authors: Yasuaki Wada, Bo Lönnerdal
    Abstract:

    Purpose of review Human Milk contains a variety of bioactive Proteins, and some of the bioactivities are exerted only after Proteins are digested in the gastrointestinal tract. This review aims to overview recent studies on bioactive peptides in Human Milk and gastric digesta of breast-fed infants. Recent findings Milk protein-derived peptides are endogenously present in Human Milk, and some of them have been reported to be bioactive peptides, such as a homologue of caseinophosphopeptide, an antimicrobial peptide, and an immunomodulatory peptide. A larger number of peptides are identified in gastric aspirates from breast-fed infants, and bioactive peptides such as angiotensin I-converting enzyme-inhibitory peptides, an antioxidative peptide, opioid agonist peptides are only found in the digesta of Human Milk but not in Human Milk per se. Casein is the greatest source of released bioactive peptides. Summary Technological advances have considerably increased our capability to identify and characterize peptides derived from Human Milk Proteins. However, their physiological significance and the roles of these bioactive peptides in growth and development of breast-fed infants have not yet been sufficiently elucidated, and further in-vivo experiments and clinical trials are warranted.

  • bioactive Proteins in Human Milk potential benefits for preterm infants
    Clinics in Perinatology, 2017
    Co-Authors: Bo Lönnerdal
    Abstract:

    Human Milk contains many bioactive Proteins that are likely to be involved in the better outcomes of breast-fed infants compared with those fed infant formula. Bovine Milk Proteins or protein fractions may be able to provide some of these benefits and may, therefore, be used for preterm infants. Recombinant Human Milk Proteins are likely to exert bioactivities similar to those of the native Human Milk Proteins, but considerable research is needed before they can be used in routine care of preterm infants.

  • Bioactive peptides derived from Human Milk Proteins - mechanisms of action
    Journal of Nutritional Biochemistry, 2014
    Co-Authors: Yasuaki Wada, Bo Lönnerdal
    Abstract:

    Human Milk contains a multitude of bioactive Proteins with very diverse functions, which are beneficial for the rapidly growing neonate. The large variety of bioactivities is accomplished by the combination of bioactive Proteins per se and gastrointestinal release of bioactive peptides derived from them. The bioactivities exerted by these peptides include enhancement of mineral absorption, immunomodulation, opioid, antihypertensive and antimicrobial activities. Notably, several of the activities are not attributed to the parental Proteins, but exclusively to released bioactive peptides. This article reviews studies on bioactive peptides derived from major Human Milk Proteins, such as caseins, α-lactalbumin and lactoferrin, during gastrointestinal digestion. Studies of bovine Milk counterparts are also cited as a comparison. © 2014.

  • Bioactive Proteins in Human Milk: Mechanisms of Action
    The Journal of Pediatrics, 2010
    Co-Authors: Bo Lönnerdal
    Abstract:

    Human Milk contains a multitude of bioactive Proteins, with very diverse functions. Some of these Proteins are involved in the synthesis and expression of Milk, but the majority appears to have evolved to provide physiological activities in the breast-fed infant. These activities are exerted by a wide variety of mechanisms and have largely been unraveled by in vitro studies. To be active in the gastrointestinal tract, these Proteins must be able to resist proteolytic degradation, at least for some time. We have evaluated the Human Milk Proteins lactoferrin, haptocorrin, α 1 -antitrypsin, and transforming growth factor -β in an in vitro digestion model, mimicking the conditions of the infant gastrointestinal milieu. These bioactive Proteins are resistant against proteolysis and can remain intact or as larger fragments through passage of the gastrointestinal tract. In vitro digestibility assays can be helpful to assess which Human Milk Proteins can resist proteolysis and to what extent.

  • recombinant Human Milk Proteins
    Protein and Energy Requirements in Infancy and Childhood Ho Chi Min City VietNam November 20-24 2005., 2006
    Co-Authors: Bo Lönnerdal
    Abstract:

    Human Milk provides Proteins that benefit newborn infants. They not only provide amino acids, but also facilitate the absorption of nutrients, stimulate growth and development of the intestine, modu

David C. Dallas - One of the best experts on this subject based on the ideXlab platform.

  • differences in Human Milk peptide release along the gastrointestinal tract between preterm and term infants
    Clinical Nutrition, 2020
    Co-Authors: Robert L Beverly, Robert K Huston, Andi M Markell, Elizabeth A Mcculley, Rachel L Martin, David C. Dallas
    Abstract:

    Summary Background & aims Preterm infants are born with a gastrointestinal tract insufficiently developed to digesting large quantities of Human Milk Proteins. Peptides released from the digestion of Human Milk Proteins have been identified with bioactivities that may be beneficial to the developing infant. However, it is unknown how prematurity affects total and bioactive peptide release along the gastrointestinal tract. The aim of this study was to compare Milk peptide release from Milk to stomach to stool between preterm and term infants. Methods Milk, gastric, and stool samples were collected from preterm infants as early collection (days 8 and 9 of life) and late collection (days 21 and 22 of life), and from term infants as early collection. Milk peptides were extracted from the samples and identified using Orbitrap mass spectrometry. Peptide abundance and count were compared across digestion and between the three infant groups at each stage of digestion. Results Total Milk peptide count and abundance increased from Milk to stomach then decreased in stool. Total peptide release was similar among the three infant groups for Milk and stool samples. In the stomach, preterm early collection had significantly higher peptide abundance and count than the other two groups. Patterns for peptide release from individual Milk Proteins were distinct from total peptide release both across digestion and among the infant groups. When analyzing single peptides, term early collection gastric samples had significantly higher peptide abundance than preterm early collection for a known antimicrobial peptide, QELLLNPTHQIYPVTQPLAPVHNPISV. Conclusions Preterm and term infants digest Milk Proteins differently along their gastrointestinal tracts. While preterm infants released more total peptides in the stomach, term infants released specific bioactive peptides at higher abundance. We identified a region at the C-terminus of β-casein that is conserved from Milk through stool and from which are released known and potential antimicrobial peptides.

  • release of functional peptides from mother s Milk and fortifier Proteins in the premature infant stomach
    PLOS ONE, 2018
    Co-Authors: Soren D Nielsen, Mark A Underwood, Robert L Beverly, David C. Dallas
    Abstract:

    Digestion of Milk Proteins in the premature infant stomach releases functional peptides; however, which peptides are present has not been reported. Premature infants are often fed a combination of Human Milk and bovine Milk fortifiers, but the variety of functional peptides released from both Human and bovine Milk Proteins remains uncharacterized. This study applied peptidomics to investigate the peptides released in gastric digestion of mother's Milk Proteins and supplemental bovine Milk Proteins in premature infants. Peptides were assessed for homology against a database of known functional peptides-Milk Bioactive Peptide Database. The peptidomic data were analyzed to interpret which proteases most likely released them from the parent protein. We identified 5,264 unique peptides from bovine and Human Milk Proteins within Human Milk, fortifier or infant gastric samples. Plasmin was predicted to be the most active protease in Milk, while pepsin or cathepsin D were predicted to be most active in the stomach. Alignment of the peptide distribution showed a different digestion pattern between Human and bovine Proteins. The number of peptides with high homology to known functional peptides (antimicrobial, angiotensin-converting enzyme-inhibitory, antioxidant, immunomodulatory, etc.) increased from Milk to the premature infant stomach and was greater from bovine Milk Proteins than Human Milk Proteins. The differential release of bioactive peptides from Human and bovine Milk Proteins may impact overall health outcomes in premature infants.

  • Relative number of peptides identified from Proteins in Human Milk and infant gastric.
    2018
    Co-Authors: Soren D Nielsen, Mark A Underwood, Robert L Beverly, David C. Dallas
    Abstract:

    Relative count (A) and relative ion intensity (B) of peptides identified in Human Milk and preterm infants gastric from either bovine Milk Proteins (bovine), Human Milk Proteins (Human), sorted according to the total peptide release among all samples. Results are shown as mean ± standard error. CASB, β-casein; OSTP, osteopontin; CASA1, αs1-casein; PIGR, polymeric immunoglobulin receptor; CEL, bile salt-activated lipase; BT1A1, butyrophilin subfamily 1 member A1; TRFL, lactoferrin; CASK, κ-casein; XDH, xanthine dehydrogenase/oxidase; LALBA, α-lactalbumin.

  • Milk Proteins Are Predigested Within the Human Mammary Gland
    Journal of Mammary Gland Biology and Neoplasia, 2017
    Co-Authors: Soren D Nielsen, Robert L Beverly, David C. Dallas
    Abstract:

    Previous work demonstrates that proteases present in Human Milk release hundreds of peptides derived from Milk Proteins. However, the question of whether Human Milk protein digestion begins within the mammary gland remains incompletely answered. The primary objective of this study was to determine whether proteolytic degradation of Human Milk Proteins into peptides begins within the mammary gland. The secondary objectives were to determine which Milk proteases participate in the proteolysis and to predict which released peptides have bioactivity. Lactating mothers ( n  = 4) expressed their Milk directly into a mixture of antiproteases on ice followed by immediate freezing of the Milk to limit post-expression protease activity. Samples were analyzed for their peptide profiles via mass spectrometry and database searching. Peptidomics-based protease prediction and bioactivity prediction were each performed with several different approaches. The findings demonstrate that Human Milk contains more than 1,100 unique peptides derived from Milk protein hydrolysis within the mammary gland. These peptides derived from 42 Milk Proteins and included 306 potential bioactive peptides. Based on the peptidomics data, plasmin was predicted to be the Milk protease most active in the hydrolysis of Human Milk Proteins within the mammary gland. Milk proteases actively cleave Milk Proteins within the mammary gland, initiating the release of functional peptides. Thus, the directly breastfed infant receives partially pre-digested Proteins and numerous bioactive peptides.

  • premature infants have lower gastric digestion capacity for Human Milk Proteins than term infants
    Journal of Pediatric Gastroenterology and Nutrition, 2017
    Co-Authors: Veronique Demersmathieu, Mark A Underwood, Robyn Borghese, David C. Dallas
    Abstract:

    OBJECTIVES Whether premature infants have lower gastric protein digestive capacity than term infants and the extent to which Human Milk proteases contribute to overall gastric digestion are unknown and were investigated in this study. METHODS Human Milk and infant gastric samples were collected from 16 preterm (24-32 wk gestational age) and 6 term (38-40 wk gestational age) mother-infant pairs within a range of 5 to 42 days postnatal age. For each pair, an aliquot of Human Milk was adjusted to pH 4.5 and incubated for 2 hours at 37 °C to simulate the gastric conditions without pepsin (Milkinc). Their gastric protein digestion capacity was measured as proteolysis (free N-terminals) and protease activities. Two-way analysis of variance followed by Tukey post hoc test was applied to compare measurements between preterm and term infants as well as among Human Milk, Milkinc, and gastric samples. RESULTS Measurements of gastric protein digestion were significantly lower in preterm infants than term infants. Overall Milk protease activity did not differ between Human Milk samples from term- and preterm-delivering mothers. As protease activity did not increase with simulated gastric incubation, Milk proteases likely contributed minimally to gastric digestion. CONCLUSIONS Preterm infants have lower gastric protein digestion capacity than term infants, which could impair nutrient acquisition. Human Milk proteases contribute minimally to overall gastric digestion. The limited activity of Milk proteases suggests that these enzymes cannot compensate for the premature infant's overall lower gastric protein digestion.

Carlito B Lebrilla - One of the best experts on this subject based on the ideXlab platform.

  • Human Milk Proteins and their glycosylation exhibit quantitative dynamic variations during lactation
    Journal of Nutrition, 2019
    Co-Authors: Elisha Goonatilleke, Jincui Huang, Jennifer T. Smilowitz, Bruce J German, Carlito B Lebrilla
    Abstract:

    BACKGROUND Proteins in Human Milk are essential and known to support the growth, development, protection, and health of the newborn. These Proteins are highly modified by glycans that are currently being recognized as vital to protein structure, stability, function, and health of the intestinal mucosa. Although Milk Proteins have been studied, the quantitative changes in Milk Proteins and their respective site-specific glycosylation are unknown. OBJECTIVE This study expanded the analytical tools for Milk Proteins and their site-specific glycosylation and applied these tools to a large cohort to determine changes in individual protein concentrations and their site-specific N-glycosylation across lactation. DESIGN A tandem mass spectrometry method was applied to 231 breast-Milk samples from 33 mothers in Davis, California, obtained during 7 different periods of lactation. Dynamic changes in the absolute abundances of Milk Proteins, as well as variation in site-specific N-glycosylation of individual Proteins, were quantified. RESULTS α-Lactalbumin, β-casein, k-casein, and α-antitrypsin were significantly increased from colostrum to transitional Milk (4.37 ± 1.33 g/L to 6.41 ± 0.72 g/L, 2.25 ± 0.86 g/L to 2.59 ± 0.78 g/L, 1.33 ± 0.44 g/L to 1.60 ± 0.39 g/L, and 0.09 ± 0.10 g/L to 0.11 ± 0.04 g/L, respectively; P < 0.002). α-Lactalbumin (37%), β-casein (9%), and lysozyme (159%) were higher in mature Milk than in colostrum. Glycans exhibited different behavior. Fucosylated glycans of lactoferrin and high-mannose, undecorated, fucosylated, sialylated, and combined fucosylated + sialylated glycans of secretory immunoglobulin A increased during lactation even when the concentrations of the parent Proteins decreased. CONCLUSIONS Proteins in healthy mothers vary dynamically through lactation to support the development of infants. Individual Milk Proteins carried unique glycan modifications that varied systematically in structure even with site specificity. The role of glycosylation in Human Milk Proteins will be important in understanding the functional components of Human Milk. This trial was registered at clinicaltrials.gov as NCT01817127.

  • quantitation of Human Milk Proteins and their glycoforms using multiple reaction monitoring mrm
    Analytical and Bioanalytical Chemistry, 2017
    Co-Authors: Jincui Huang, Jennifer T. Smilowitz, Muchena J Kailemia, Elisha Goonatilleke, Evan A Parker, Qiuting Hong, Rocchina Sabia, Bruce J German, Carlito B Lebrilla
    Abstract:

    Human Milk plays a substantial role in the child growth, development and determines their nutritional and health status. Despite the importance of the Proteins and glycoProteins in Human Milk, very little quantitative information especially on their site-specific glycosylation is known. As more functions of Milk Proteins and other components continue to emerge, their fine-detailed quantitative information is becoming a key factor in Milk research efforts. The present work utilizes a sensitive label-free MRM method to quantify seven Milk Proteins (α-lactalbumin, lactoferrin, secretory immunoglobulin A, immunoglobulin G, immunoglobulin M, α1-antitrypsin, and lysozyme) using their unique peptides while at the same time, quantifying their site-specific N-glycosylation relative to the protein abundance. The method is highly reproducible, has low limit of quantitation, and accounts for differences in glycosylation due to variations in protein amounts. The method described here expands our knowledge about Human Milk Proteins and provides vital details that could be used in monitoring the health of the infant and even the mother. Graphical Abstract The glycopeptides EICs generated from QQQ.

  • quantitation of Human Milk Proteins and their glycoforms using multiple reaction monitoring mrm
    Analytical and Bioanalytical Chemistry, 2017
    Co-Authors: Jincui Huang, Jennifer T. Smilowitz, Muchena J Kailemia, Elisha Goonatilleke, Evan A Parker, Qiuting Hong, Rocchina Sabia, Bruce J German, Carlito B Lebrilla
    Abstract:

    Human Milk plays a substantial role in the child growth, development and determines their nutritional and health status. Despite the importance of the Proteins and glycoProteins in Human Milk, very little quantitative information especially on their site-specific glycosylation is known. As more functions of Milk Proteins and other components continue to emerge, their fine-detailed quantitative information is becoming a key factor in Milk research efforts. The present work utilizes a sensitive label-free MRM method to quantify seven Milk Proteins (α-lactalbumin, lactoferrin, secretory immunoglobulin A, immunoglobulin G, immunoglobulin M, α1-antitrypsin, and lysozyme) using their unique peptides while at the same time, quantifying their site-specific N-glycosylation relative to the protein abundance. The method is highly reproducible, has low limit of quantitation, and accounts for differences in glycosylation due to variations in protein amounts. The method described here expands our knowledge about Human Milk Proteins and provides vital details that could be used in monitoring the health of the infant and even the mother.

  • Predicting the important enzymes in Human breast Milk digestion
    Journal of Agricultural and Food Chemistry, 2014
    Co-Authors: Nora Khaldi, Saumya Wickramasinghe, Vinod Vijayakumar, David C. Dallas, Juan F. Medrano, Denis C. Shields, Carlito B Lebrilla, Andres Guerrero, Jennifer T. Smilowitz, J. Bruce German
    Abstract:

    Human Milk is known to contain several proteases, but little is known about whether these enzymes are active, which Proteins they cleave, and their relative contribution to Milk protein digestion in vivo. This study analyzed the mass spectrometry-identified protein fragments found in pooled Human Milk by comparing their cleavage sites with the enzyme specificity patterns of an array of enzymes. The results indicate that several enzymes are actively taking part in the digestion of Human Milk Proteins within the mammary gland, including plasmin and/or trypsin, elastase, cathepsin D, pepsin, chymotrypsin, a glutamyl endopeptidase-like enzyme, and proline endopeptidase. Two Proteins were most affected by enzyme hydrolysis: β-casein and polymeric immunoglobulin receptor. In contrast, other highly abundant Milk Proteins such as α-lactalbumin and lactoferrin appear to have undergone no proteolytic cleavage. A peptide sequence containing a known antimicrobial peptide is released in breast Milk by elastase and cathepsin D.

Yasuaki Wada - One of the best experts on this subject based on the ideXlab platform.

  • bioactive peptides derived from Human Milk Proteins an update
    Current Opinion in Clinical Nutrition and Metabolic Care, 2020
    Co-Authors: Yasuaki Wada, Bo Lönnerdal
    Abstract:

    Purpose of review Human Milk contains a variety of bioactive Proteins, and some of the bioactivities are exerted only after Proteins are digested in the gastrointestinal tract. This review aims to overview recent studies on bioactive peptides in Human Milk and gastric digesta of breast-fed infants. Recent findings Milk protein-derived peptides are endogenously present in Human Milk, and some of them have been reported to be bioactive peptides, such as a homologue of caseinophosphopeptide, an antimicrobial peptide, and an immunomodulatory peptide. A larger number of peptides are identified in gastric aspirates from breast-fed infants, and bioactive peptides such as angiotensin I-converting enzyme-inhibitory peptides, an antioxidative peptide, opioid agonist peptides are only found in the digesta of Human Milk but not in Human Milk per se. Casein is the greatest source of released bioactive peptides. Summary Technological advances have considerably increased our capability to identify and characterize peptides derived from Human Milk Proteins. However, their physiological significance and the roles of these bioactive peptides in growth and development of breast-fed infants have not yet been sufficiently elucidated, and further in-vivo experiments and clinical trials are warranted.

  • Bioactive peptides derived from Human Milk Proteins - mechanisms of action
    Journal of Nutritional Biochemistry, 2014
    Co-Authors: Yasuaki Wada, Bo Lönnerdal
    Abstract:

    Human Milk contains a multitude of bioactive Proteins with very diverse functions, which are beneficial for the rapidly growing neonate. The large variety of bioactivities is accomplished by the combination of bioactive Proteins per se and gastrointestinal release of bioactive peptides derived from them. The bioactivities exerted by these peptides include enhancement of mineral absorption, immunomodulation, opioid, antihypertensive and antimicrobial activities. Notably, several of the activities are not attributed to the parental Proteins, but exclusively to released bioactive peptides. This article reviews studies on bioactive peptides derived from major Human Milk Proteins, such as caseins, α-lactalbumin and lactoferrin, during gastrointestinal digestion. Studies of bovine Milk counterparts are also cited as a comparison. © 2014.

Jennifer T. Smilowitz - One of the best experts on this subject based on the ideXlab platform.

  • Human Milk Proteins and their glycosylation exhibit quantitative dynamic variations during lactation
    Journal of Nutrition, 2019
    Co-Authors: Elisha Goonatilleke, Jincui Huang, Jennifer T. Smilowitz, Bruce J German, Carlito B Lebrilla
    Abstract:

    BACKGROUND Proteins in Human Milk are essential and known to support the growth, development, protection, and health of the newborn. These Proteins are highly modified by glycans that are currently being recognized as vital to protein structure, stability, function, and health of the intestinal mucosa. Although Milk Proteins have been studied, the quantitative changes in Milk Proteins and their respective site-specific glycosylation are unknown. OBJECTIVE This study expanded the analytical tools for Milk Proteins and their site-specific glycosylation and applied these tools to a large cohort to determine changes in individual protein concentrations and their site-specific N-glycosylation across lactation. DESIGN A tandem mass spectrometry method was applied to 231 breast-Milk samples from 33 mothers in Davis, California, obtained during 7 different periods of lactation. Dynamic changes in the absolute abundances of Milk Proteins, as well as variation in site-specific N-glycosylation of individual Proteins, were quantified. RESULTS α-Lactalbumin, β-casein, k-casein, and α-antitrypsin were significantly increased from colostrum to transitional Milk (4.37 ± 1.33 g/L to 6.41 ± 0.72 g/L, 2.25 ± 0.86 g/L to 2.59 ± 0.78 g/L, 1.33 ± 0.44 g/L to 1.60 ± 0.39 g/L, and 0.09 ± 0.10 g/L to 0.11 ± 0.04 g/L, respectively; P < 0.002). α-Lactalbumin (37%), β-casein (9%), and lysozyme (159%) were higher in mature Milk than in colostrum. Glycans exhibited different behavior. Fucosylated glycans of lactoferrin and high-mannose, undecorated, fucosylated, sialylated, and combined fucosylated + sialylated glycans of secretory immunoglobulin A increased during lactation even when the concentrations of the parent Proteins decreased. CONCLUSIONS Proteins in healthy mothers vary dynamically through lactation to support the development of infants. Individual Milk Proteins carried unique glycan modifications that varied systematically in structure even with site specificity. The role of glycosylation in Human Milk Proteins will be important in understanding the functional components of Human Milk. This trial was registered at clinicaltrials.gov as NCT01817127.

  • quantitation of Human Milk Proteins and their glycoforms using multiple reaction monitoring mrm
    Analytical and Bioanalytical Chemistry, 2017
    Co-Authors: Jincui Huang, Jennifer T. Smilowitz, Muchena J Kailemia, Elisha Goonatilleke, Evan A Parker, Qiuting Hong, Rocchina Sabia, Bruce J German, Carlito B Lebrilla
    Abstract:

    Human Milk plays a substantial role in the child growth, development and determines their nutritional and health status. Despite the importance of the Proteins and glycoProteins in Human Milk, very little quantitative information especially on their site-specific glycosylation is known. As more functions of Milk Proteins and other components continue to emerge, their fine-detailed quantitative information is becoming a key factor in Milk research efforts. The present work utilizes a sensitive label-free MRM method to quantify seven Milk Proteins (α-lactalbumin, lactoferrin, secretory immunoglobulin A, immunoglobulin G, immunoglobulin M, α1-antitrypsin, and lysozyme) using their unique peptides while at the same time, quantifying their site-specific N-glycosylation relative to the protein abundance. The method is highly reproducible, has low limit of quantitation, and accounts for differences in glycosylation due to variations in protein amounts. The method described here expands our knowledge about Human Milk Proteins and provides vital details that could be used in monitoring the health of the infant and even the mother. Graphical Abstract The glycopeptides EICs generated from QQQ.

  • quantitation of Human Milk Proteins and their glycoforms using multiple reaction monitoring mrm
    Analytical and Bioanalytical Chemistry, 2017
    Co-Authors: Jincui Huang, Jennifer T. Smilowitz, Muchena J Kailemia, Elisha Goonatilleke, Evan A Parker, Qiuting Hong, Rocchina Sabia, Bruce J German, Carlito B Lebrilla
    Abstract:

    Human Milk plays a substantial role in the child growth, development and determines their nutritional and health status. Despite the importance of the Proteins and glycoProteins in Human Milk, very little quantitative information especially on their site-specific glycosylation is known. As more functions of Milk Proteins and other components continue to emerge, their fine-detailed quantitative information is becoming a key factor in Milk research efforts. The present work utilizes a sensitive label-free MRM method to quantify seven Milk Proteins (α-lactalbumin, lactoferrin, secretory immunoglobulin A, immunoglobulin G, immunoglobulin M, α1-antitrypsin, and lysozyme) using their unique peptides while at the same time, quantifying their site-specific N-glycosylation relative to the protein abundance. The method is highly reproducible, has low limit of quantitation, and accounts for differences in glycosylation due to variations in protein amounts. The method described here expands our knowledge about Human Milk Proteins and provides vital details that could be used in monitoring the health of the infant and even the mother.

  • Comparative Proteomics of Human and Macaque Milk Reveals Species-Specific Nutrition during Postnatal Development
    2015
    Co-Authors: Kristen L. Beck, Jennifer T. Smilowitz, Darren Weber, Brett S. Phinney, Katie Hinde, Bo Lönnerdal, Ian Korf, Danielle G. Lemay
    Abstract:

    Milk has been well established as the optimal nutrition source for infants, yet there is still much to be understood about its molecular composition. Therefore, our objective was to develop and compare comprehensive Milk proteomes for Human and rhesus macaques to highlight differences in neonatal nutrition. We developed a Milk proteomics technique that overcomes previous technical barriers including pervasive post-translational modifications and limited sample volume. We identified 1606 and 518 Proteins in Human and macaque Milk, respectively. During analysis of detected protein orthologs, we identified 88 differentially abundant Proteins. Of these, 93% exhibited increased abundance in Human Milk relative to macaque and include lactoferrin, polymeric immunoglobulin receptor, alpha-1 antichymotrypsin, vitamin D-binding protein, and haptocorrin. Furthermore, Proteins more abundant in Human Milk compared with macaque are associated with development of the gastrointestinal tract, the immune system, and the brain. Overall, our novel proteomics method reveals the first comprehensive macaque Milk proteome and 524 newly identified Human Milk Proteins. The differentially abundant Proteins observed are consistent with the perspective that Human infants, compared with nonHuman primates, are born at a slightly earlier stage of somatic development and require additional support through higher quantities of specific Proteins to nurture Human infant maturation

  • Predicting the important enzymes in Human breast Milk digestion
    Journal of Agricultural and Food Chemistry, 2014
    Co-Authors: Nora Khaldi, Saumya Wickramasinghe, Vinod Vijayakumar, David C. Dallas, Juan F. Medrano, Denis C. Shields, Carlito B Lebrilla, Andres Guerrero, Jennifer T. Smilowitz, J. Bruce German
    Abstract:

    Human Milk is known to contain several proteases, but little is known about whether these enzymes are active, which Proteins they cleave, and their relative contribution to Milk protein digestion in vivo. This study analyzed the mass spectrometry-identified protein fragments found in pooled Human Milk by comparing their cleavage sites with the enzyme specificity patterns of an array of enzymes. The results indicate that several enzymes are actively taking part in the digestion of Human Milk Proteins within the mammary gland, including plasmin and/or trypsin, elastase, cathepsin D, pepsin, chymotrypsin, a glutamyl endopeptidase-like enzyme, and proline endopeptidase. Two Proteins were most affected by enzyme hydrolysis: β-casein and polymeric immunoglobulin receptor. In contrast, other highly abundant Milk Proteins such as α-lactalbumin and lactoferrin appear to have undergone no proteolytic cleavage. A peptide sequence containing a known antimicrobial peptide is released in breast Milk by elastase and cathepsin D.