Development of an immunofluorometric assay and quantification of human kallikrein 7 in tissue extracts and biological fluids.
BACKGROUND
Human kallikrein 7 (hK7), also known as human stratum corneum chymotryptic enzyme, is a chymotrypsin-like serine protease first identified in human skin extracts and predicted to be a secreted protease. The aim of this study was to develop a sensitive and specific immunoassay for hK7 and to examine the distribution of hK7 in tissue extracts and biological fluids.


METHODS
Recombinant hK7 was produced in human embryonic kidney cells (HEK293T) and purified by a three-step column chromatographic procedure. The purified hK7 was injected into mice for antibody generation. A sandwich-type immunoassay was developed with the anti-hK7 monoclonal antibodies.


RESULTS
The assay had imprecision (CV) <10% through the dynamic range of 0.2-20 microg/L and had no detectable cross-reactivity from other members in the human kallikrein gene family. Highest concentrations were found in skin, esophagus, and kidney. hK7 was also found in amniotic fluid, ascites from ovarian cancer patients, breast milk, cerebrospinal fluid, saliva, seminal plasma, serum, sweat, synovial fluid, and urine.


CONCLUSIONS
This study describes the first ELISA-type immunoassay for hK7 protein quantification. hK7 is found many human tissues and in various biological fluids.
Kishi
Tadaaki
T
Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada.
Soosaipillai
Antoninus
A
Grass
Linda
L
Little
Sheila P
SP
Johnstone
Edward M
EM
Diamandis
Eleftherios P
EP
D000328:Adult; D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000737:chemistry; D001826:Body Fluids / Q000737:chemistry*; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D007118:Immunoassay; D007610:Kallikreins / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification; D008297:Male; D013058:Mass Spectrometry; D051379:Mice; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000276:immunology / Q000302:isolation & purification; D012680:Sensitivity and Specificity; D014020:Tissue Extracts / Q000737:chemistry*
D000911:Antibodies, Monoclonal; D011994:Recombinant Proteins; D014020:Tissue Extracts; D007610:Kallikreins