TY - JOUR
T1 - A protease inhibitor of the Kunitz family from skin secretions of the tornato frog, Dyscophus guineti (Microhylidae)
AU - Conlon, J. Michael
AU - Kim, Joseph B.
N1 - Funding Information:
We thank Dr. Donald Babin for amino acid analyses and Eva Lovas for mass spectrometry measurements. This work was supported by a grant from the National Science Foundation (EPS-9720643).
PY - 2000/12/29
Y1 - 2000/12/29
N2 - Norepinephrine-stimulated skin secretions of the tomato frog, Dyscophus guineti, contained a trypsin inhibitor whose primary structure was established as: SPAEVCF LPK10 ESGLCRARAL20 RYYYDRGDGK30 CEEFIYGGCG40 GNGNNY KSLL50 TCKISCE. This amino acid sequence identifies the peptide as a member of the Kunitz/bovine pancreatic trypsin inhibitor (BPTI) family and demonstrates that selective evolutionary pressure has acted to conserve those domains in the molecule (corresponding to positions 12-18 and 34-39 in BPTI) that interact with trypsin. Extracellular proteases produced by pathogenic microorganisms play important roles in facilitating invasion of the host and broad spectrum antimicrobial activity of BPTI has been described. Cationic, amphipathic α-helical antimicrobial peptides of the magainin type, important in the defense strategy of several species of frog, were not detected in the skin secretions. We speculate, therefore, that synthesis of a proteinase inhibitot in the skin of the tomato frog may be a component of an alternative strategy of this animal to defend itself against microorganisms.
AB - Norepinephrine-stimulated skin secretions of the tomato frog, Dyscophus guineti, contained a trypsin inhibitor whose primary structure was established as: SPAEVCF LPK10 ESGLCRARAL20 RYYYDRGDGK30 CEEFIYGGCG40 GNGNNY KSLL50 TCKISCE. This amino acid sequence identifies the peptide as a member of the Kunitz/bovine pancreatic trypsin inhibitor (BPTI) family and demonstrates that selective evolutionary pressure has acted to conserve those domains in the molecule (corresponding to positions 12-18 and 34-39 in BPTI) that interact with trypsin. Extracellular proteases produced by pathogenic microorganisms play important roles in facilitating invasion of the host and broad spectrum antimicrobial activity of BPTI has been described. Cationic, amphipathic α-helical antimicrobial peptides of the magainin type, important in the defense strategy of several species of frog, were not detected in the skin secretions. We speculate, therefore, that synthesis of a proteinase inhibitot in the skin of the tomato frog may be a component of an alternative strategy of this animal to defend itself against microorganisms.
KW - Amphibia
KW - Antimicrobial peptide
KW - Bovine pancreatic trypsin inhibitor
KW - Kunitz
KW - Protease inhibitor
KW - Skin secretions
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U2 - 10.1006/bbrc.2000.4052
DO - 10.1006/bbrc.2000.4052
M3 - Article
C2 - 11162457
AN - SCOPUS:0034731414
SN - 0006-291X
VL - 279
SP - 961
EP - 964
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 3
ER -