title: Soluble Expression of Bladder Cancer Biomarker Matrix Metalloproteinase 1.
abstract: BACKGROUND
  Matrix metalloproteinase 1 (MMP1) has been shown as a novel unique biomarker of bladder cancer in urine. MMP1 can only be detected using conventional and time-consuming methods, such as ELISA and Western. Refolded MMP1 has been achieved and used in probe screen for many years, while there is no clinical application for MMP1 detection until now. Soluble expression of MMP1 is necessary in urine detection.
  
  
  METHODS
  cDNA of MMP1 has been isolated from human embryonic kidney 293(HEK293) cells. The catalytic domain of MMP1 is expressed as fusion protein with Escherichia coli thioredoxin (TrxA). The 30 kDa recombinant proteins were purified by Ni-chelating chromatography. The activity of soluble MMP1 was determined and compared with refolded MMP1 by zymography.
  
  
  RESULTS
  Compared with refolded MMP1, TrxA can increase the solubility of MMP1. The soluble MMP1 has the same protein sequences with refolded MMP1 and increased 1.54-fold of gelatin-degradation activities than refolded MMP1.
  
  
  CONCLUSIONS
  Successfully soluble expression of MMP1 has been achieved by fusion expression and will make progress in discovering specific molecular probes against MMP1.
authors.affiliation: Department of Urinary Surgery, China-Japan Union Hospital, Jilin University, Changchun, China.
authors.forename: Xuefei
authors.initials: X
authors.lastname: Jin
authors.affiliation: Department of Endocrinology, China-Japan Union Hospital, Jilin University, Changchun 130033, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Department of Urinary Surgery, China-Japan Union Hospital, Jilin University, Changchun, China.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Urinary Surgery, China-Japan Union Hospital, Jilin University, Changchun, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Jin
authors.affiliation: The Retired People in Army Residents of Jilin, Changchun, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Liu
authors.affiliation: Department of Urinary Surgery, China-Japan Union Hospital, Jilin University, Changchun, China.
authors.forename: Xiangbo
authors.initials: X
authors.lastname: Kong
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism*; D005822:Genetic Vectors / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D002479:Inclusion Bodies / Q000378:metabolism; D020781:Matrix Metalloproteinase 1 / Q000302:isolation & purification / Q000378:metabolism*; D012995:Solubility; D001749:Urinary Bladder Neoplasms / Q000201:enzymology*
chemical_list: D014408:Biomarkers, Tumor; C522360:MMP1 protein, human; D020781:Matrix Metalloproteinase 1
keywords: MMP1; biomarker; bladder cancer; prokaryotic expression