Functional characterization of Kunitz-type protease inhibitor Pr-mulgins identified from New Guinean Pseudechis australis

A four-domain Kunitz-type proteinase inhibitor from Solen grandis is implicated in immune response

“…In present study, there were four Kunitz domains in SgKunitz, among of them the P1 residue in Kunitz domain 1 was leucine, while the relevant residues in Kunitz domain 2 and 3 were arginine and lysine, respectively, which indicated SgKunitz might inhibit the activity of trypsin and chymotrypsin synchronously. Such deduction was confirmed by our subsequent result, which manifested the recombinant SgKunitz could inhibit the activities of both aforementioned enzymes, and this result was consisted with the Kunitztype SPI Pr-mulgins-2 in Pseudechis australis [31]. However, except for the aforementioned residues, the P1 position in Kunitz domain 4 was glutamic acid that had not been reported before, whether it could increase the inhibitory spectrum or not was still an unknown question that needed further illustration.…”

“…The existence of the Kunitz domain and the conserved sequence and structure motifs, together with the high sequence identity, strongly suggested that SgKunitz should be a member of Kunitz-type SPI family. Meanwhile, the similar hallmarks both in sequence and structure also suggesting SgKunitz might perform the same function as other Kunitz-type SPIs [29,31]. Detecting the tissue specific expression pattern of SgKunitz gene would benefit understanding its potential role in inhibitory behavior and the functions in immune response.…”

“…Several isolated or recombinant Kunitztype SPIs from invertebrates could effectively inhibit the activities of SPs [29,31,36]. For instance, Kunitz-type SPI purified from hemolymph of Galleria mellonella larvae could inhibit the activities of trypsin, plasmin and kallikrein [29], while recombinant Kunitztype SPIs of silkworm exhibit effective inhibitory activity toward chymotrypsin [36].…”

Purification, characterization and molecular cloning of chymotrypsin inhibitor peptides from the venom of Burmese Daboia russelii siamensis

“…To date a number of BPTI-like superfamily serine protease inhibitors from Viperidae and Elapidae venoms have been purified or characterized [3,4,12,13,15,16,18,19,25,26,[29][30][31][32][33][34]35,36,39]. In this paper, one chymotrypsin inhibitor, BBPTI-1, was purified to homogeneity from the venom of Burmese Daboia russelli siamensis by gel filtration, cation exchange and reversed phase chromatography.…”

Discoveries of Serine Protease Inhibitors from Scorpions

“…Among all classes, the Kunitz-type inhibitors are well characterized of them, possibly due to their abundance in several creatures [13,15,16]. Many studies reported that animal venoms contain Kunitz-type serine protease inhibitors [12,[17][18][19]. Similarly, Kunitz-type as well as Ascaris-type serine protease inhibitors have been reported to be present in scorpions, and most of them have been identified by cDNA cloning and transcriptomic analysis [10,11,[20][21][22].…”