Akitsugu Senda

Chemical characterization of oligosaccharides in chimpanzee, bonobo, gorilla, orangutan, and siamang milk or colostrum

Neutral and acidic oligosaccharides were isolated from the milk or colostrum of four great ape species (chimpanzee (Pan troglodytes), bonobo (Pan paniscus), gorilla (Gorilla gorilla), and orangutan (Pongo pygmaeus)) and one lesser ape species (siamang (Symphalangus syndactylus)), and their chemical structures were characterized by (1)H-NMR spectroscopy. Oligosaccharides containing the type II unit (Gal(beta1-4)GlcNAc) were found exclusively (gorilla and siamang) or predominately (chimpanzee, bonobo, and orangutan) over those containing the type I unit (Gal(beta1-3)GlcNAc). In comparison, type I oligosaccharides predominate over type II oligosaccharides in human milk, whereas nonprimate milk almost always contains only type II oligosaccharides. The milk or colostrum of the great apes contained oligosaccharides bearing both N-glycolylneuraminic acid and N-acetylneuraminic acid, whereas human milk contains only the latter. Great ape milk, like that of humans, contained fucosylated oligosaccharides whereas siamang milk did not. Since these analyses are based on a limited number of individuals, further research on additional samples of great and lesser ape milk is needed to confirm phylogenetic patterns.

Changes in the bovine whey proteome during the early lactation period

To investigate time-dependent change in the bovine whey proteome during the early lactation period, a two-dimensional gel-based approach was used in this study. Milk samples were collected from five healthy Friesian-Holstein dairy cows up to 10 days postpartum. Spot patterns of whey proteins varied drastically from immediately after parturition to 48 h, but no significant changes occurred thereafter. Protein identification by mass spectrometry revealed that the ratios of caseins and immunoglobulins drastically decreased during 48 h postpartum, while those of lower molecular mass proteins such as α-lactalbumin and β-lactoglobulin increased. More than 100 spots were detected, being much more abundant in colostral whey than in mature milk whey. Of a total of 25 proteins identified, four, viz. zinc-α-2-glycoprotein, vitamin D-binding protein, immunoglobulin G2 chain C and β2-microglobulin, were detectable only in colostrum. Our results indicate that most of the minor whey proteins in colostrum relate to the passive immunity of newborn calves, but some of them play significant roles in nutritional supplementation of the neonate. The characteristics of whey proteins in transition imply that enhancement of innate immunity becomes more important than protection of the neonate against pathogens via passive immunity after 48 h postpartum.

Determination of Sialyl and Neutral Oligosaccharide Levels in Transition and Mature Milks of Samoan Women, Using Anthranilic Derivatization Followed by Reverse Phase High Performance Liquid Chromatography

An improved analytical method using reverse-phase high performance liquid chromatography following anthranilic acid derivatization for the measurement of each oligosaccharide level in transition (5 to 10 d lactation) and mature (21 to 155 d lactation) milks of sixteen Samoan women is described. The method was applied for the measurement of sialyl as well as neutral oligosaccharide levels. We found that disialyllacto-N-tetraose (DSLNT), sialylacto-N-tetraose c (LSTc), and 6′-sialyllactose (6′-SL) were the most abundant of the sialyl oligosaccharides. In the neutral oligosaccharide fraction, lacto-N-fucopentaose II and III combined (LNFP II+III) were the most dominant, followed by lacto-N-tetraose (LNT) and 3-fucosyllactose (3-FL). 2′-Fucosyllactose (2′-FL) and lacto-N-fucopentaose I (LNFP I) were absent in some and found at low levels in most of the Samoan women. Our study indicates that the milk oligosaccharide composition in Samoan women is similar to that of Japanese women with respect to sialyl but not to neutral oligosaccharides. The differences in neutral oligosaccharides might have a genetic origin.

Structural characterization of neutral and acidic oligosaccharides in the milks of strepsirrhine primates: greater galago, aye-aye, Coquerel’s sifaka and mongoose lemur

The structures of milk oligosaccharides were characterized for four strepsirrhine primates to examine the extent to which they resemble milk oligosaccharides in other primates. Neutral and acidic oligosaccharides were isolated from milk of the greater galago (Galagidae: Otolemur crassicaudatus), aye-aye (Daubentoniidae: Daubentonia madagascariensis), Coquerel’s sifaka (Indriidae: Propithecus coquereli) and mongoose lemur (Lemuridae: Eulemur mongoz), and their chemical structures were characterized by 1H-NMR spectroscopy. The oligosaccharide patterns observed among strepsirrhines did not appear to correlate to phylogeny, sociality or pattern of infant care. Both type I and type II neutral oligosaccharides were found in the milk of the aye-aye, but type II predominate over type I. Only type II oligosaccharides were identified in other strepsirrhine milks. α3′-GL (isoglobotriose, Gal(α1-3)Gal(β1-4)Glc) was found in the milks of Coquerel’s sifaka and mongoose lemur, which is the first report of this oligosaccharide in the milk of any primate species. 2′-FL (Fuc(α1-2)Gal(β1-4)Glc) was found in the milk of an aye-aye with an ill infant. Oligosaccharides containing the Lewis x epitope were found in aye-aye and mongoose lemur milk. Among acidic oligosaccharides, 3′-N-acetylneuraminyllactose (3′-SL-NAc, Neu5Ac(α2-3)Gal(β1-4)Glc) was found in all studied species, whereas 6′-N-acetylneuraminyllactose (6′-SL-NAc, Neu5Ac(α2-6)Gal(β1-4)Glc) was found in all species except greater galago. Greater galago milk also contained 3′-N-glycolylneuraminyllactose (3′-SL-NGc, Neu5Gc(α2-3)Gal(β1-4)Glc). The finding of a variety of neutral and acidic oligosaccharides in the milks of strepsirrhines, as previously reported for haplorhines, suggests that such constituents are ancient rather than derived features, and are as characteristic of primate lactation is the classic disaccharide, lactose.

Short communication: Evidence for the presence of a putative odorant-binding protein in bovine colostrum

Using a combination of PAGE and mass spectrometry for protein identification, we obtained evidence that a putative odorant-binding protein, designated hypothetical protein LOC517854, occurs in bovine colostrum. This protein, termed as a putative bovine colostral odorant-binding protein (bcOBP), consists of 172 AA residues, including a putative 16-AA signal peptide. The theoretical isoelectric point value and molecular mass of the full-length sequence of bcOBP were calculated to be 4.57 and 19604.18, respectively. The highest sequence similarity (83%) was observed with a potential pheromone transporter, Allergen Bos d 2. An odorant-binding protein derived from bovine nasal mucosa showed relatively low sequence similarity (52%) against bcOBP. Its biological function is unclear, but pheromone transport could be considered. This is the first report of a putative odorant-binding protein in bovine colostrum.

Cloning, Monoclonal Antibody Production, and Bodily Distribution Pattern of a Bovine Lipocalin

A bovine lipocalin, previously identified as a putative odorant-binding protein in bovine colostrum (bcOBP), was cloned and expressed, and its monoclonal antibody was established. bcOBP was constantly secreted into milk on day of parturition until at least 10 d postpartum at a concentration of 181±39 μg/L. Besides milk, bcOBP occurred in the nasal mucus, saliva, amniotic fluid, vaginal discharge, and blood plasma. Despite its low concentration, the distribution pattern and the finding that bcOBP harbored a characteristic sequence motif, CxxxC, which is conserved among insect and mammal pheromone binding proteins, suggest that bcOBP functions as a pheromone carrier. The presence of bcOBP in the plasma at varied concentrations depending on the lactation period does not exclude the possibility that bcOBP is secreted into milk from the blood. Cross-reactivity of the monoclonal antibody indicated presence of proteins homologous to bcOBP in the colostrum of farm animals of Cetartiodactyla.