Distance between the basic group of the amino acid residue's side chain in position P1 of trypsin inhibitor CMTI-III and Asp189 in the substrate pocket of trypsin has an essential influence on the inhibitory activity.
Three new analogues of trypsin inhibitor CMTI-III were synthesized by the solid-phase method: [Lys5]-CMTI-III, [Orn5]CMTI-III and [Dab5]CMTI-III. Only one analogue with L-lysine residue in position P1 showed inhibitory activity of the same order of magnitude as did wild CMTI-III. Two remaining analogues were completely inactive. A conclusion was drawn that the distance between the basic group of the amino acid residue's side chain in position P1 of the trypsin inhibitor CMTI-III and Asp189 in the substrate pocket of trypsin plays an essential role for the trypsin-inhibitor interaction.
Jaśkiewicz
A
A
Faculty of Chemistry, University of Gdańsk, Poland.
Lesner
A
A
Rózycki
J
J
Rodziewicz
S
S
Rolka
K
K
Ragnarsson
U
U
Kupryszewski
G
G
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D011487:Protein Conformation; D012984:Software; D014357:Trypsin / Q000737:chemistry* / Q000378:metabolism; D014361:Trypsin Inhibitors / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology
C081870:CMTI protein, Cucurbita maxima; D010940:Plant Proteins; D014361:Trypsin Inhibitors; D014357:Trypsin