A comment on ATPase driven streaming in a reconstituted contractile system

The production of chemo-mechanical effects in a reconstituted system of purified muscle proteins had been studied. It was found that the "streaming" effects observed (by previous workers) in the circular slit of a stream cell were observed under conditions where the absence of artefacts could not be guaranteed. In particular, convective motion motion, due to small temperature gradients is shown to be present, resulting in streaming even in the absence of essential components of the system such as ATP. Temperature inhomogeneities of the order of only 0.1 K . mm-1 are sufficient to cause motion, and any future experiments on streaming must be thermally homogeneous to a greater accuracy than this if valid conclusions are to be drawn.