Apolipoprotein D is the major protein component in cyst fluid from women with human breast gross cystic disease.
GCDFP(gross-cystic-disease-fluid protein)-24, a progesterone-binding protein present in large amounts in cyst fluid from human breast gross cystic disease, was purified in a one-step procedure by size-exclusion h.p.l.c. Peptide fragments obtained by trypsin digestion of the intact protein were purified by reverse-phase h.p.l.c. and analysed for their amino acid composition and subjected to automated Edman degradation. A search of the National Biomedical Research Foundation Data Bank revealed that all the sequenced tryptic peptides from protein GCDFP-24 matched perfectly with regions present in the amino acid sequence determined for human apolipoprotein D. Additional data on N-terminal sequence of the unblocked proteins, carbohydrate-attachment sites, amino acid composition and molecular-mass estimations supported the identity between both molecules. On the basis of this identity a possible role of apolipoprotein D in progesterone transport is proposed.
Balbín
M
M
Departamento de Biología Funcional, Facultad de Medicina, Universidad de Oviedo, Spain.
Freije
J M
JM
Fueyo
A
A
Sánchez
L M
LM
López-Otín
C
C
D000595:Amino Acid Sequence; D001053:Apolipoproteins / Q000737:chemistry / Q000378:metabolism*; D053399:Apolipoproteins D; D001826:Body Fluids / Q000737:chemistry* / Q000378:metabolism; D002352:Carrier Proteins; D005260:Female; D005348:Fibrocystic Breast Disease / Q000378:metabolism*; D006023:Glycoproteins; D006801:Humans; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism; D011374:Progesterone / Q000378:metabolism; D014357:Trypsin / Q000378:metabolism
C024328:APOD protein, human; D001053:Apolipoproteins; D053399:Apolipoproteins D; D002352:Carrier Proteins; D006023:Glycoproteins; D026901:Membrane Transport Proteins; D009363:Neoplasm Proteins; D010455:Peptides; D011374:Progesterone; D014357:Trypsin