A proteomic approach to evaluate the butyrophilin gene family expression in human milk fat globule membrane.
Human butyrophilin (BTN) expression in milk fat globule (MFGM) was evaluated using two dimensional electrophoresis (2-DE) as the separation technique, and peptide mass mapping by matrix-assisted laser desorption/ionisation-mass spectrometry (MALDI-MS) as the identification tool. Since milk composition changes throughout lactation time, 2-DE maps in the pH range 4-7 of colostral MFGM and mature MFGM were compared, showing only slight differences in BTN spot distribution. The BTN gene family codes for seven proteins (BTN, BTN2A1, BTN2A2, BTN2A3, BTN3A1, BTN3A2, BTN3A3), their presence in human tissues has to date been evaluated only at a transcriptional level. Among 70 spots, analyzed and identified by MALDI-MS, 13 spots were identified as BTN spots and only one as a fragment of BTN2A1. BTN was present in multiple glycoforms, and two smaller BTN forms of about 45 kDa were also identified. We propose an array of BTNs on human MFGM, which could provide breast-fed infants with immune molecules during the neonatal period.
Dipartimento di Scienze e Tecnologie Avanzate, Università del Piemonte Orientale, Alessandria, Italy. cavalett@unipmn.it
Maria
M
Cavaletto
Maria Gabriella
MG
Giuffrida
Donatella
D
Fortunato
Laura
L
Gardano
Giuseppina
G
Dellavalle
Lorenzo
L
Napolitano
Carlo
C
Giunta
Enrico
E
Bertino
Claudio
C
Fabris
Amedeo
A
Conti
D000595:Amino Acid Sequence; D000818:Animals; D000071797:Butyrophilins; D022162:Cytoplasmic Vesicles / Q000737:chemistry / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D005223:Fats / Q000737:chemistry*; D005260:Female; D006801:Humans; D007425:Intracellular Membranes / Q000737:chemistry* / Q000378:metabolism; D013058:Mass Spectrometry; D008562:Membrane Glycoproteins / Q000235:genetics*; D008895:Milk, Human / Q000737:chemistry*; D008969:Molecular Sequence Data; D005810:Multigene Family; D040901:Proteomics; D016415:Sequence Alignment
C000605700:BTN2A2 protein, human; D000071797:Butyrophilins; D005223:Fats; D008562:Membrane Glycoproteins