Discovery and development of direct thrombin inhibitors the binding site for the globular amino-terminal domain and exosite 1 is the binding site for the acidic carboxy-terminal domain of hirudin. Native hirudin, a 65-amino-acid polypeptide, is produced in the parapharyngeal glands of medicinal leeches. Hirudins today are produced by recombinant biotechnology using yeast. These recombinant hirudins lack a sulfate group at Tyr-63 and are therefore called desulfatohirudins. They have a 10-fold lower binding affinity to thrombin compared to native hirudin, but remain a highly specific inhibitor of thrombin and have an inhibition constant for thrombin in the picomolar range. Renal clearance and degradation account for the most part
Creatures 2 near the oceans. Scattered throughout the world are various seed launchers, which can be used to replenish stocks if any life-forms become extinct. Albia also has four seasons: Spring, Summer, Winter and Autumn, and boasts its very own climate, with weather such as snow mainly occurring during the colder months, and rain mostly during the Spring. The game also has an on-screen thermometer, allowing the player to monitor Albia's temperature at all times. Creatures 2's release was widely anticipated. It is likely that around 450,000 copies of the original Creatures had been sold by the time the game was released,