Characterization of Anopheles gambiae transglutaminase 3 (AgTG3) and its native substrate Plugin.
J Biol Chem
; 288(7): 4844-53, 2013 Feb 15.
Article
de En
| MEDLINE
| ID: mdl-23288850
ABSTRACT
Male Anopheles mosquitoes coagulate their seminal fluids via cross-linking of a substrate, called Plugin, by the seminal transglutaminase AgTG3. Formation of the "mating plug" by cross-linking Plugin is necessary for efficient sperm storage by females. AgTG3 has a similar degree of sequence identity (~30%) to both human Factor XIII (FXIII) and tissue transglutaminase 2 (hTG2). Here we report the solution structure and in vitro activity for the cross-linking reaction of AgTG3 and Plugin. AgTG3 is a dimer in solution and exhibits Ca(2+)-dependent nonproteolytic activation analogous to cytoplasmic FXIII. The C-terminal domain of Plugin is predominantly α-helical with extended tertiary structure and oligomerizes in solution. The specific activity of AgTG3 was measured as 4.25 × 10(-2) units mg(-1). AgTG3 is less active than hTG2 assayed using the general substrate TVQQEL but has 8-10× higher relative activity when Plugin is the substrate. Mass spectrometric analysis of cross-linked Plugin detects specific peptides including a predicted consensus motif for cross-linking by AgTG3. These results support the development of AgTG3 inhibitors as specific and effective chemosterilants for A. gambiae.
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Transglutaminases
/
Anopheles
Type d'étude:
Prognostic_studies
Limites:
Animals
Langue:
En
Journal:
J Biol Chem
Année:
2013
Type de document:
Article
Pays d'affiliation:
États-Unis d'Amérique