Abstract: The present invention relates to a method for producing recombinant human prethrombin-2 protein and having human ?-thrombin activity by the plant-based expression systems.

Abstract: An apparatus and a method for sealingly engaging an upper chamber lid and a lower chamber lid of a vacuum process chamber together without leakage are provided. In the apparatus, an upper chamber lid is connected to a support frame by an universal joint such that a perfect alignment between the upper chamber lid and the lower camber lid can be achieved by making 360° movement of the upper chamber lid. The support frame is further provided with a plurality of compressible spring members, i.e., at least 3 or 4 spring members that are mounted to the support frame and projected downwardly for pressing on a top surface of the upper camber lid and achieving a vacuum-tight seal between the upper lid and the lower lid. The novel use of the universal joint and the plurality of compressible springs therefore enables the present invention apparatus to achieve a vacuum-tight seal between two chambers halves in a vacuum process chamber.