Loxosceles
bites have been associated with characteristic dermonecrotic lesions with gravitational spreading and systemic manifestations.
Venom primarily comprises
peptides and
protein molecules (5-40 kDa) with multiple
biological activities. Although poorly studied,
metalloproteases have been identified in
venoms of several Loxosceles species, presenting proteolytic effects on extracellular matrix components. The characterization of an
Astacin-like
protease (LALP) in Loxosceles intermedia
venom was the first report of an
Astacin family member as a component of animal
venom. Recently, these
proteases were described as a gene family in L. intermedia, Loxosceles laeta and Loxosceles gaucho. Herein, the whole
venom complexity of these three Loxosceles species was analyzed using two-dimensional electrophoresis (2DE). Subproteomes of LALPs were explored through 2DE immunostaining using anti-LALP1
antibodies and 2DE
gelatin zymogram.
Proteins presented molecular masses ranging from 24 to 29 kDa and the majority of these molecules had basic or neutral isoelectric points (6.89-9.93). Likewise, the measurement of gelatinolytic effects of
Loxosceles venom using
fluorescein-
gelatin showed that the three
venoms have distinct proteolytic activities. The
metalloprotease fibrinogenolytic activities were also evaluated. All
venoms showed fibrinogenolytic activity with different proteolytic effects on Aα and Bβ chains of
fibrinogen. The results reported herein suggest that the LALP family is larger than indicated in previously published data and that the complex profile of the gelatinolytic activity reflects their relevance in
loxoscelism. Furthermore, our investigation implicates the
brown spider venom as a source of
Astacin-like
proteases for use in
loxoscelism studies, cell biology research and biotechnological applications.