Overexpression of a human prostate-specific glandular kallikrein, hK2, in E. coli and generation of antibodies

• Published in: Molecular and cellular endocrinology Vol. 109; no. 2; pp. 237 - 241
• Main Authors: Saedi, Mohammad S., Cass, Michelle M.J., Goel, Amita S., Grauer, Lana, Hogen, Kristine L., Okaneya, Toshikazu, Griffin, Beverly Y., Klee, George G., Young, Charles Y.-F., Tindall, Donald J.
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier Ireland Ltd 01-04-1995
• Subjects: Amino Acid Sequence; Animals; Antibodies; Antibodies, Monoclonal - immunology; Antibodies, Monoclonal - isolation & purification; Base Sequence; Cloning and expression; DNA, Complementary - genetics; Escherichia coli; Gene Expression Regulation; hK2; Human kallikrein; Humans; Kallikreins - biosynthesis; Kallikreins - genetics; Kallikreins - immunology; Molecular Sequence Data; Prostate specific antigen; Rabbits; Recombinant Fusion Proteins - biosynthesis; Recombinant Fusion Proteins - immunology; Tissue Kallikreins; Human kallikrein; Prostate specific antigen; Antibodies; Cloning and expression; hK2
• ISSN: 0303-7207; 1872-8057
• DOI: 10.1016/0303-7207(95)03508-5

The genomic and the cDNA clones of human glandular kallikrein (hK2), a member of the kallikrein family, have been isolated; however, the hK2 protein has not yet been identified and characterized. The deduced sequence of hK2 is highly homologous to prostate specific antigen (PSA), a widely accepted prognostic indicator of prostate carcinoma. Also, hK2 mRNA, like PSA mRNA, is exclusively expressed in prostatic epithelia. These two properties make hK2 a potentially useful marker for studying prostate cancer. In this paper, we describe for the first time the overexpression of the entire hK2 protein (pre-pro hK2:pphK2) in the
E. coli system. Our system yields high levels of authentic pphK2 (as determined by partial amino acid sequence analysis) comprising about 40% of total cellular protein. pphK2 was purified to near homogeneity by preparative SDS/PAGE and used to generate anti-pphK2 antibodies in rabbits. The antibodies recognize the recombinant hK2 protein and a major band of -34 kDa in seminal fluid.