Tryptogalinin Is a Tick Kunitz Serine Protease Inhibitor with a Unique Intrinsic Disorder

0397485 - BC 2014 RIV US eng J - Článek v odborném periodiku
Valdés, James J. - Schwarz, Alexandra - Cabeza de Vaca, I. - Calvo, E. - Pedra, J. H. F. - Guallar, V. - Kotsyfakis, Michalis
Tryptogalinin Is a Tick Kunitz Serine Protease Inhibitor with a Unique Intrinsic Disorder.
PLoS ONE. Roč. 8, č. 5 (2013), e62562. ISSN 1932-6203. E-ISSN 1932-6203
Grant CEP: GA ČR GPP302/11/P798; GA MŠMT LH12002; GA ČR GAP502/12/2409; GA MŠMT(CZ) EE2.3.30.0032
Institucionální podpora: RVO:60077344
Klíčová slova: mast-cell tryptase * Ixodes scapularis * sialostatin-L
Kód oboru RIV: EB - Genetika a molekulární biologie
Impakt faktor: 3.534, rok: 2013

Background: A salivary proteome-transcriptome project on the hard tick Ixodes scapularis revealed that Kunitz peptides are the most abundant salivary proteins. Ticks use Kunitz peptides (among other salivary proteins) to combat host defense mechanisms and to obtain a blood meal. Most of these Kunitz peptides, however, remain functionally uncharacterized, thus limiting our knowledge about their biochemical interactions. Results: We discovered an unusual cysteine motif in a Kunitz peptide. This peptide inhibits several serine proteases with high affinity and was named tryptogalinin due to its high affinity for beta-tryptase. Compared with other functionally described peptides from the Acari subclass, we showed that tryptogalinin is phylogenetically related to a Kunitz peptide from Rhipicephalus appendiculatus, also reported to have a high affinity for b-tryptase. Using homology-based modeling (and other protein prediction programs) we were able to model and explain the multifaceted function of tryptogalinin. The N-terminus of the modeled tryptogalinin is detached from the rest of the peptide and exhibits intrinsic disorder allowing an increased flexibility for its high affinity with its inhibiting partners (i.e., serine proteases). Conclusions: By incorporating experimental and computational methods our data not only describes the function of a Kunitz peptide from Ixodes scapularis, but also allows us to hypothesize about the molecular basis of this function at the atomic level.
Trvalý link: http://hdl.handle.net/11104/0225141