Effect of YM-47141, A New Inhibitor Produced by Flexzbactor SR Q17897, Onelastase

Abstract

YM-47141, a peptidic compound recently isolated from Flexibactor sp. Q17897, strongly inhibited human leukocyte elastase (HLE) with K_i value 2.1 × 10⁻⁷ M. Unlike other serine protease inhibitors, YM-47141 exhibited relatively weak effects on cathepsin G and α-chymotrypsin and its inhibitory K_i values were 9.2 × 10⁻⁶ M and 1.3 × 10⁻⁶ M, respectively. It bad little, or no inhibitory effect on plasmin, thrombin, trypsin and kallikrein (IC₅₀ > 10⁻⁴ M). The inhibition of HLE by YM-47141 was reversible and of a mixed type.

Key Words: :

• Elastase
• serine protease
• protease inhibitor
• pulmonary emphysema
• YM-47141
• Flexibactor sp. Q17897