Purification and characterization of a cytolytic pore-forming protein from granules of cloned lymphocytes with natural killer activity

Cell. 1986 Mar 28;44(6):849-59. doi: 10.1016/0092-8674(86)90007-3.


A cytolytic pore-forming protein (PFP, perforin) was purified from isolated granules of cloned NK-like cytolytic cells, which showed an apparent Mr of 70-75 kd (reduced) and 62-66 kd (nonreduced). Cytolysis produced by this protein occurred only in the presence of Ca2+ and was accompanied by the formation of membrane lesions of 160 A diameter. The purified protein depolarized cells and made lipid vesicles leaky to monovalent and divalent ions. This protein formed large, voltage insensitive and nonselective ion channels in planar bilayers that remained preferentially in the open state. The channels were heterogeneous in size distribution averaging 400 pS/U in 0.1 M NaCl. The membrane lesions formed by PFP were morphologically and functionally similar to those formed by intact NK-like cells and their granules. This PFP could be released from granules during cell killing, followed by its polymerization on target membranes to form large transmembrane pores.

Publication types

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

MeSH terms

  • Calcium / pharmacology
  • Cell Membrane Permeability / drug effects
  • Centrifugation, Density Gradient
  • Clone Cells
  • Cytotoxicity, Immunologic
  • Hemolysis / drug effects
  • Humans
  • Ion Channels / physiology
  • Killer Cells, Natural / analysis*
  • Killer Cells, Natural / immunology
  • Kinetics
  • Lipid Bilayers / metabolism
  • Membrane Glycoproteins*
  • Membrane Potentials
  • Membrane Proteins / isolation & purification*
  • Membrane Proteins / pharmacology
  • Molecular Weight
  • Perforin
  • Polymers
  • Pore Forming Cytotoxic Proteins


  • Ion Channels
  • Lipid Bilayers
  • Membrane Glycoproteins
  • Membrane Proteins
  • Polymers
  • Pore Forming Cytotoxic Proteins
  • Perforin
  • Calcium