Two‐dimensional gel electrophoretic analysis of plasma proteins from a patient bitten by a rattlesnake

We have studied changes in plasma proteins in a patient bitten by a western diamondback rattlesnake ( Crotalus atrox ). Samples obtained at intervals during recovery were analyzed by “low resolution” two dimensional (2‐D) gel electrophoresis, a method which resolves at least 50 plasma components. The results show three days of complete afibrinogenemia, followed by gradual return of fibrinogen to a normal level. Both α‐ and β‐ lipoproteins also appeared altered or decreased in concentration during this period. An anomalous change in electrophoretic mobility of a portion of complement component 3 (C3) was detected during the first 15 days, but not at day 38. This modified protein was not C3b or C3c. A short incubation of human plasma or purified C3 with venom in vitro , did not mimic in vivo effects on either fibrinogen or C3, but plasma lipoproteins were modified directly in vitro. It is possible that the in vivo effects of venom on C3 and fibrinogen, as revealed by the 2‐D gel electrophoretic method, are indirect and require release or activation of cellular proteases.