title: A Kazal-Type Serine Protease Inhibitor from the Defense Gland Secretion of the Subterranean Termite Coptotermes formosanus Shiraki.
abstract: Coptotermes formosanus is an imported, subterranean termite species with the largest economic impact in the United States. The frontal glands of the soldier caste termites comprising one third of the body mass, contain a secretion expelled through a foramen in defense. The small molecule composition of the frontal gland secretion is well-characterized, but the proteins remain to be identified. Herein is reported the structure and function of one of several proteins found in the termite defense gland secretion. TFP4 is a 6.9 kDa, non-classical group 1 Kazal-type serine protease inhibitor with activity towards chymotrypsin and elastase, but not trypsin. The 3-dimensional solution structure of TFP4 was solved with nuclear magnetic resonance spectroscopy, and represents the first structure from the taxonomic family, Rhinotermitidae. Based on the structure of TFP4, the protease inhibitor active loop (Cys(8) to Cys(16)) was identified.
authors.affiliation: Department of Biological Sciences, Division of Biochemistry and Molecular Biology, Louisiana State University and A&M College, Baton Rouge, LA 70803, United States of America.
authors.forename: Horia
authors.initials: H
authors.lastname: Negulescu
authors.affiliation: Currently at the Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, United States of America.
authors.forename: Youzhong
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Currently at the Department of Biochemistry, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY 10461, United States of America.
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Garner
authors.affiliation: Department of Chemistry, Louisiana State University and A&M College, Baton Rouge, LA 70803, United States of America.
authors.forename: Octavia Y
authors.initials: OY
authors.lastname: Goodwin
authors.affiliation: Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, United States of America.
authors.forename: Gregg
authors.initials: G
authors.lastname: Henderson
authors.affiliation: Department of Chemistry, Louisiana State University and A&M College, Baton Rouge, LA 70803, United States of America; Department of Biological Sciences, Division of Biochemistry and Molecular Biology, Louisiana State University and A&M College, Baton Rouge, LA 70803, United States of America.
authors.forename: Roger A
authors.initials: RA
authors.lastname: Laine
authors.affiliation: Department of Chemistry, Louisiana State University and A&M College, Baton Rouge, LA 70803, United States of America.
authors.forename: Megan A
authors.initials: MA
authors.lastname: Macnaughtan
mesh_terms: D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary / Q000235:genetics; D020049:Isoptera / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D015842:Serine Proteinase Inhibitors / Q000737:chemistry*
chemical_list: D018076:DNA, Complementary; D015842:Serine Proteinase Inhibitors