Alkaline serine proteases from Helicoverpa armigera: potential candidates for industrial applications

Abstract

We characterized trypsin- and chymotrypsin-like serine alkaline proteases from cotton bollworm, Helicoverpa armigera, for their probable potential application as additives in various bio-formulations. Purification was achieved by using hydroxylapatite, DEAE sephadex and CM sephadex columns, which resulted in increased enzyme activity by 13.76- and 14.05-fold for trypsin and chymotrypsin, respectively. Michaelis-Menten constants (K ) for substrates of trypsin and chymotrypsin, BApNA and SAAPFpNA, were found to be 1.25 and 0.085 mM, correspondingly. Fluorescent zymogram analysis indicated the presence of five trypsin bands with molecular masses of ∼21, 25, 38, 40, and 66 kDa and two chymotrypsin bands with molecular masses of ∼29 and 34 kDa in SDS-PAGE. The optimum pH was 10.0 and optimum temperature was 50°C for proteolytic activity for the purified proteases. The proteases were inhibited by synthetic inhibitors such as PMSF, aprotonin, leupeptin, pefabloc, and antipain. TLCK and TPCK inhibited about 94 and 90% of trypsin and chymotrypsin activity, respectively, while EDTA, EGTA, E64, pepstatin, idoacetamide, and bestatin did not affect the enzymes. The purified enzymes exhibited high stability and compatibility with metal ions; oxidizing, reducing, and bleaching agents; organic solvents; and commercial detergents. Short life cycles, voracious feeding behavior, and production of multiple forms of proteases in the midgut with rapid catalytic activity and chemostability can serve H. armigera as an excellent alternative source of industrially important proteases for use as additives in stain removers, detergents, and other bio-formulations. Identification of enzymes with essential industrial properties from insect species could be a bioresource.

Schistocerca piceifrons piceifrons (Orthoptera: Acrididae) as a Source of Compounds of Biotechnological and Nutritional Interest

“…It has been suggested recently that some insects can be important and diverse suppliers of proteases, either endogenously, or as obtained from the microorganisms associated with host-insects’ digestive tract, these findings support the potential of insects as a source of enzymes for application in the food industry (Mika et al 2015). In this context, the detection of IPA from S. p. piceifrons is indicative of its potential regarding the intestinal proteolytic enzymes, which are considered suitable candidates for product development, such is the case of active ingredients now used by the laundry and detergent industries (Akbar and Sharma 2017). Our detection of trypsin-like enzymes in S. p. piceifrons agrees with those reported for other orthopterans, such as Teleogryllus commodus (Walker), Gryllus bimaculatus (De Geer), and P. beltrani (Torres-Castillo et al 2015b, Woodring and Weidlich 2016), which suggest this catalytic mechanism is common in this insect order.…”

Characterization of thermostable alkaline proteases from Bacillus infantis SKS1 isolated from garden soil

“…Alkaline protease producing bacteria are ubiquitously found in natural [ 13 – 16 ] and, anthropogenic man-made environment [ 17 ]. As compared to plants and animals as a source of proteases [ 6 , 7 ], it is more propitious to use microbes because of their enormous diversity, expeditious growth, requirement for limited space during cultivation and easy genetic manipulation [ 18 , 19 ]. Bacillus is one of the most vital genera that have been used for alkaline proteases production because of their chemoorganotrophic characteristics, tremendous growth rates, secretion of extracellular enzyme into media and are safe to handle [ 2 , 20 ].…”

Development of stimuli-responsive nano-based pesticides: emerging opportunities for agriculture

“…Special attention has been focused on enzymes present in the salivary glands and mid-gut of larvae and insects, in the soil, and produced by phytopathogenic fungi. The salivary glands and mid-gut of insects mainly contain carbohydrases and proteases [15, 56, 57]. In soil, the enzymes most frequently found are urease, alkaline phosphatase, dehydrogenase, and catalase [2].…”