Radiobacterphage neutralization anomaly in relation to cations

Abstract

Antiserum neutralization of PS-192 and PR-1001 bacteriophages of Agrobacterium radiobacter produced anomalous and first-order inactivation curves, respectively. Maximum neutralization rates were obtained with about 0.1 M NaCl solution. Neutralization velocity constants (K values) with the PR-1001: SPR-1001(3) system in 0.1 M of Na+, K+, Li+, Cs+, and NH4+ were 24, 28, 23, 22, and 22, respectively. Bacteriophage neutralization was suppressed by 0.01 M concentration of eight divalent cations in the presence of 0.1 M NaCl solution. Differences in the Na+, K+, Ca2+, and Mg2+ concentrations in sera of 12 rabbits ranged up to 31, 61, 18, and 22% respectively. Small amounts of Ca2+ intensified the anomaly observed with phage PS-192. This cation also produced a deviation from a first-order neutralization ordinarily characteristic for the PR-1001: SPR-1001(6) phage: antiserum system. A small concentration of Na-citrate, which exerted no detrimental effect on phage PS-192, corrected the anomaly usually typical for PS-192: PR-1001(6) system. These findings suggest that as the neutralization proceeds the cation concentration in the reaction mixture may gradually increase as a result of antigen: antibody union, thus bringing about a progressive deceleration in the rate of radiobacterphage neutralization.