JSJ-1, an anti-spermidine monoclonal antibody with potential clinical applications.

Polyamines have been implicated in a wide variety of functions including nucleic acid synthesis and protein synthesis. Their levels have been shown to increase in response to cell growth and differentiation. Use of polyamines as prognostic indicators of proliferative disease conditions has been hindered by the lack of suitable rapid and sensitive assays. We report the characterization of an anti-spermidine antibody, JSJ-1, with novel putrescine cross reactivity. JSJ-1 cross-reacts more strongly with putrescine (11%) than with spermine (6%). This suggests that the aminobutyl group common to both putrescine and spermidine is an important element in the antibody-antigen interaction. We have demonstrated that antibody-spermidine binding is effected by increased ionic strength. This finding is consistent with the antibody-antigen interaction being ionic. The JSJ-1 antibody has been successfully used to detect increased polyamine levels in clinical serum samples and identify those with increased polyamine levels.