Proteomic analysis of human prostasomes.
BACKGROUND
Prostasomes are secretory particles in human seminal fluid. Other than a microscopic description of these secretory particles and an incomplete two-dimensional gel electrophoresis (2DE) study, little is known about the composition of proteins in prostasomes.


METHODS
We employed a direct iterative approach using Gas phase fractionation and microcapillary HPLC-tandem mass spectrometry (microLC-MS/MS) to catalogue the prostasome proteome.


RESULTS
We identified 139 proteins that can be divided into the following categories: (1). enzymes (33.8% of total), (2). transport/structural (19.4% of total), (3). GTP proteins (14.4% of total), (4). chaperone proteins (5.8% of total), (5). signal transduction proteins (17.3% of total), and (6). unannotated proteins (9.4% of total). A total of 128 of the 139 proteins have not previously been described as prostasomal.


CONCLUSIONS
The proteins identified can be used as reference dataset in future work comparing prostasome proteins between normal and pathological states such as prostate cancer, benign prostatic hyperplasia, prostatitis, and infertility.
Institute for Systems Biology, Seattle, Washington 98103, USA.
Angelita G
AG
Utleg
Eugene C
EC
Yi
Tao
T
Xie
Paul
P
Shannon
James T
JT
White
David R
DR
Goodlett
Leroy
L
Hood
Biaoyang
B
Lin
D004798:Enzymes / Q000032:analysis; D019204:GTP-Binding Proteins / Q000032:analysis; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D018832:Molecular Chaperones / Q000032:analysis; D040901:Proteomics; D022142:Secretory Vesicles / Q000737:chemistry* / Q000201:enzymology*; D012661:Semen / Q000737:chemistry* / Q000201:enzymology* / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology
D004798:Enzymes; D018832:Molecular Chaperones; D019204:GTP-Binding Proteins