Comparative characterisation of poly(ADP-ribose) polymerase-1 from two mammalian species with different life span

Exp Gerontol. 2000 Oct;35(8):989-1002. doi: 10.1016/s0531-5565(00)00134-0.

Abstract

DNA damage induced in higher eukaryotes by alkylating agents, oxidants or ionising radiation triggers the synthesis of protein-conjugated poly(ADP-ribose) catalysed by poly(ADP-ribose) polymerase-1 (PARP-1). Previously, cellular poly(ADP-ribosyl)ation capacity has been shown to correlate positively with the life span of mammalian species [Proc. Natl. Acad. Sci. USA 89 (1992) 11,759-11,763]. Here, we have tested whether this correlation results from differences in kinetic parameters of the enzymatic activity of PARP-1. We therefore compared recombinant enzymes, expressed in a baculovirus system, from rat and man as two mammalian species with extremely divergent life span. In standard activity assays performed in the presence of histones as poly(ADP-ribose) acceptors both enzymes showed saturation kinetics with [NAD(+)]. The kinetic parameters (k(cat), k(m) and k(cat)/k(m)) of the two enzymes were not significantly different. However, in assays assessing the auto-poly(ADP-ribosyl)ation reaction, both enzymes displayed second-order kinetics with respect to [PARP-1], and up to two-fold higher specific activity was observed for human versus rat PARP-1. We conclude that the correlation of poly(ADP-ribosyl)ation capacity with life span is not reflected in the kinetic parameters, but that subtle differences in primary structure of PARP-1 from mammalian species of different longevity may control the extent of the automodification reaction.

Publication types

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

MeSH terms

  • Animals
  • Baculoviridae / genetics
  • DNA Damage
  • Humans
  • Kinetics
  • Longevity / physiology*
  • Poly(ADP-ribose) Polymerases / genetics
  • Poly(ADP-ribose) Polymerases / isolation & purification
  • Poly(ADP-ribose) Polymerases / metabolism*
  • Rats
  • Recombinant Proteins / genetics
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism
  • Species Specificity

Substances

  • Recombinant Proteins
  • Poly(ADP-ribose) Polymerases