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Endogenous Protease Inhibitors (endogenous + protease_inhibitor)

Distribution by Scientific Domains
Chemistry75%

Selected Abstracts

EFFECTS OF MUSCLE PROTEASES, ENDOGENOUS PROTEASE INHIBITORS AND MYOFIBRIL FRAGMENTATION ON POSTMORTEM AGING OF GOAT MEAT

JOURNAL OF FOOD BIOCHEMISTRY, Issue 3 2006
N.S. NAGARAJ
ABSTRACT The present study was conducted to evaluate the extent of postmortem proteolysis in longissimus dorsi, biceps femoris, semimembranosus and semitendinosus goat muscles on postmortem aging at an ambient (27C) temperature. The activities of calpains and calpastatin were determined after separation on a (diethylamino)ethyl,Sephacel column (Sigma, St. Louis, MO) and cathepsin (B, B + L and H) by carboxymethyl,Sepharose column (Sigma). The results showed that the decrease in calpain I and calpastatin activities was significantly higher than that of calpain II. Cathepsin B, B + L, H and cystatin were found to fall by 30,80% after 12 h, whereas cathepsin D decreased significantly in all the muscles. The disappearance of titin 1 and nebulin, and the appearance of a 30-kDa component were confirmed by Western blot analysis. The appearance of the 30-kDa component reported here explains the time-induced structural changes of myofibrils. The Z-line degradation had occurred by 6 h postmortem. Cathepsins are not stable compared to calpains during postmortem aging, and both enzymes may play a significant role in the proteolysis of myofibrillar proteins at ambient temperature. [source]

Protease inhibitors and reproduction of reniform nematode in pineapple

ANNALS OF APPLIED BIOLOGY, Issue 1 2009
C. Rabovich
Abstract Endogenous protease inhibitors (PIs) in the roots of Smooth Cayenne pineapple clones may affect the growth of the plant-parasitic nematode Rotylenchulus reniformis. In pineapple, reniform population densities remain atypically near preplant levels for 6,9 months after pineapple planting. A potted plant experiment was conducted to determine if the PI present in pineapple roots affected nematode reproduction and possibly account for the observed nematode field population dynamics. Pineapple PI activity increased for the first 6 months after planting and was higher in nematode-inoculated plants. Nematode reproduction, however, was not correlated to PI activity. In a second experiment, PI activity was concentrated in the portion of the roots nearest the pineapple butt where nematode population densities were highest. The behaviour of the PI in pineapple roots suggested a defensive role, such as systemic acquired resistance, against R. reniformis. [source]

Exogenous and endogenous protease inhibitors in the gut of the fall armyworm larvae, Spodoptera frugiperda

ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 2 2010
Digali Lwalaba
Abstract A dose-dependent inhibition of endogenous trypsin and aminopeptidase occurs in the lumen of Spodoptera frugiperda after feeding L6 larvae exogenous inhibitors soybean trypsin inhibitor (SBTI), tosyl-L-lysine chloromethyl ketone-HCl (TLCK), or bestatin, respectively, for 3 days. TLCK inhibits trypsin in tissue extracts and in secretions more strongly than SBTI. The aminopeptidase released into the lumen (containing the peritrophic membrane) is strongly inhibited by bestatin, but the membrane-bound enzyme is not. A bound enzyme may be more resistant to an inhibitor than unbound. A cross-class elevation of aminopeptidase activity occurs in response to ingested trypsin inhibitor, but there was no cross-class effect of aminopeptidase inhibitor (bestatin) on trypsin activity. An endogenous trypsin and aminopeptidase inhibitor is present in the lumen and ventricular cells. The strength of the endogenous trypsin inhibition seems to be in the same range as that resulting from ingestion of the exogenous inhibitor SBTI. In some insect species, considerable trypsin secretion occurs in unfed as well as in fed animals, and endogenous protease inhibitors might function to protect the ventricular epithelium by inactivation of trypsin when less food is available. © 2010 Wiley Periodicals, Inc. [source]