A Review and Proposed Nomenclature for Major Proteins of the Milk-Fat Globule Membrane,

Abstract

The characteristics and possible functions of the most abundant proteins associated with the bovine milk-fat globule membrane are reviewed.Under the auspices of the Milk Protein Nomenclature Committee of the ADSA, a revised nomenclature for the major membrane proteins is proposed and discussed in relation to earlier schemes.We recommend that proteins be assigned specific names as they are identified by molecular cloning and sequencing techniques.The practice of identifying proteins according to their M r , electrophoretic mobility, or staining characteristics should be discontinued, except for uncharacterized proteins.The properties and amino acid sequences of the following proteins are discussed in detail: MUC1, xanthine dehydrogenase/oxidase, CD36, butyrophilin, adipophilin, periodic acid Schiff 6/7 (PAS 6/7), and fatty acid binding protein.In addition, a compilation of less abundant proteins associated with the bovine milk-fat globule membrane is presented.(Key words: milk-fat globule membrane proteins, nomenclature, review) Abbreviation key: ADPH = adipophilin, ADRP = adipose differentiation-related protein, BTN = butyrophilin, FABP = fatty acid binding protein, IgC1 = constant 1-type Ig domain, IgI = intermediate-type Ig domain, MDGI = mammary-derived growth inhibitor, MFGM = milk-fat globule membrane, MHC = major histocompatibility complex, PAS = periodic acid/Schiff, PAS 6/ 7 = periodic acid Schiff 6/7, VNTR = variable number tandem repeat, XDH/XO = xanthine dehydrogenase/ oxidase.The purpose of this report is to summarize the identities, characteristics, and sequences of the major proteins associated with the bovine milk-fat globule membrane (MFGM).This compilation follows a decade of