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

Mol Cell Endocrinol. 1995 Apr 1;109(2):237-41. 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 approximately 34 kDa in seminal fluid.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antibodies, Monoclonal / immunology
  • Antibodies, Monoclonal / isolation & purification
  • Base Sequence
  • DNA, Complementary / genetics
  • Escherichia coli
  • Gene Expression Regulation*
  • Humans
  • Kallikreins / biosynthesis*
  • Kallikreins / genetics
  • Kallikreins / immunology
  • Molecular Sequence Data
  • Rabbits
  • Recombinant Fusion Proteins / biosynthesis*
  • Recombinant Fusion Proteins / immunology
  • Tissue Kallikreins


  • Antibodies, Monoclonal
  • DNA, Complementary
  • Recombinant Fusion Proteins
  • Kallikreins
  • Tissue Kallikreins