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
Bicyclomycin Bicyclomycin Bicyclomycin (Bicozamycin) is a broad spectrum antibiotic active against Gram-negative bacteria and the Gram-positive bacterium, "Micrococcus luteus" that was isolated from "Streptomyces sapporonesis" and "Streptomyces aizumenses" in 1972. It belongs to a class of naturally occurring 2,5-diketopiperazines, that are among the most numerous of all the naturally occurring peptide antibiotics. This clinically useful antibiotic is rapidly absorbed in man when given intramuscularly, has low toxicity and has been used to treat diarrhea in humans and bacterial diarrhea in calves and pigs. Bicyclomycin is the only known selective inhibitor of Rho, a RecA-type ATPase, which is a transcription termination factor