Purification and cDNA sequence of an inducible nitric oxide synthase from a human tumor cell line

Biochemistry. 1993 Nov 2;32(43):11600-5. doi: 10.1021/bi00094a017.


A combination of cytokines induced the expression of nitric oxide synthase (NOS) in a human colorectal adenocarcinoma cell line, DLD-1. We have purified the enzyme and examined some of its biochemical properties. An antiserum to an inducible NOS from murine macrophages cross-reacted with the DLD-1 NOS. The purified human and murine enzymes displayed a similar lack of dependence on exogenous calcium and calmodulin for activity, which contrasts with the requirement for calcium and calmodulin of purified brain and endothelial isoforms of NOS. We have also isolated a cDNA for a cytokine-induced NOS from DLD-1 cells. Sequence analysis of this cDNA and NOS cDNAs from human liver, smooth muscle, and macrophages suggests that, at the genetic level, there is a single isoform of human-inducible NOS.

MeSH terms

  • Adenocarcinoma / enzymology
  • Amino Acid Oxidoreductases / biosynthesis*
  • Amino Acid Oxidoreductases / genetics
  • Amino Acid Oxidoreductases / isolation & purification
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cell Line
  • Colorectal Neoplasms / enzymology
  • Cytokines / pharmacology
  • DNA, Complementary / chemistry
  • Enzyme Induction
  • Humans
  • Macrophages / enzymology
  • Mice
  • Molecular Sequence Data
  • Nitric Oxide Synthase
  • Polymerase Chain Reaction
  • Tumor Cells, Cultured


  • Cytokines
  • DNA, Complementary
  • Nitric Oxide Synthase
  • Amino Acid Oxidoreductases

Associated data