Proteins protease

A large number of potential reversible protease inhibitors exist (Laskowski Kato, 1980). Protein protease inhibitors like Strepromyces Subtilisin Inhibitor (SSI) (Hiromi et al, 1985) and Chymotrypsin Inhibitor (CI-2) (Jonassen, 1980 and McPhalen James, 1988) are known to be very strong inhibitors with inhibition constants at or below 10"10 M. 

Hiromi, K Akasaka, K Mitsui, Y Tonomura, B Murao, S (eds) (1985) Protein Protease Inhibitor - The Case of Streptomyces Subtilisin Inhibitor. Elsevier Amsterdam - Oxford - New York. 

Although any of these seven steps could be a druggable target, most of the antiviral agents clinically employed for non-AIDS infections act on the synthesis or assembly of either purines or pyrimidines (steps 3 and 4). For AIDS, reverse transcriptase inhibitors block transcription of the HIV RNA genome into DNA, thereby preventing synthesis of viral mRNA and protein protease inhibitors act on the synthesis of late proteins (steps 5 and 6). 

Single proteins Protease digestion, then Amperometric, H2O2 at... 

Hydrolytic enzymes Pancreatin Hydrolysis of starch (amylase), fat (lipase), and protein (protease) Porcine pancreas Digestive aid... 

Peptide mapping analysis of proteins Protease Fused-silica capillary [366]... 

Fig. 2.1 Structure of SSI subunit. (Reproduced with permission from Y., Mitsui, et al Protein Protease Inhibitor-The Case of Streptomyces Subtilisin Inhibitor (SSI) (K. Hiromi et al. ed.), p. 174, Elsevier, Amsterdam (1985)).

PROTEIN AND NON-PROTEIN PROTEASE INHIBITORS FROM PLANTS... 

Plant species (other name) (Family) Protease inhibitor protein Protease specificity (IC50) TKd, Ki1 (reactive site) Ref. 

This review has succinctly summarized what is presently known of nonprotein and protein protease inhibitors from plants. The affinities of the non-protein inhibitors for particular proteases are generally much lower than those of plant protease inhibitor proteins (PIPs). Nevertheless the non-protein protease inhibitors may provide structure/activity starting points for development of pharmaceutically useful compounds of much higher affinity. The plant PIP literature has been comprehensively surveyed in this review. However electronic databases such as EMBL and SWISSPROT contain further accessible plant PIP sequences [581]. The array of potent plant PIPs reflects the co-evolution of plant defensive proteins and insect resistance [582]. Potent, stable, protease inhibitor proteins have potential transgenic crop agriculture applications as well as potential chemotherapeutic applications. 

Since a major component of all cells is protein, proteases could be very destructive if they were not carefully controlled or compartmentalized. The potential seriousness of uncontrolled proteolysis can be recognized by the fact that ca. 10% of the proteins by weight found in human plasma are protease inhibitors. The currently recognized plasma protease inhibitors are listed in Table I (3,4). In addition to the plasma inhibitors, there are other inhibitors that are more localized and have not been as well characterized. 

The inclusion of enzyme inhibitors in a formulation may help to overcome the enzymatic activity of the epithelial barrier. Work in this field has concentrated on the use of protease inhibitors to facilitate the absorption of therapeutic peptides and proteins. Protease inhibitors demonstrating potential to increase... 

Because plants cannot escape from insect injury, many plants protect themselves by producing defense proteins. Protease inhibitors, which protect plants by inhibiting the feed digestion of insects, are well-studied defense proteins. These protease inhibitors are induced in leaves distant from points of injury, indicating that signal substances are involved in systemic resistance induction in plants. 

Solutions containing active enzymatic proteins (protease, lipase, trypsin, pepsin, prophase, or cellulase) or their mixtures, adjusted to the nature of the matrix of the solid material of biological origin [79, 83, 84]. The aim of the procedure is to break up proteins, polysaccharides, or fat chains and release the constituent amino acids, sugars, or short aliphatic chains. Enzymatic decomposition of the matrix can be considerably enhanced by application of ultrasound the process can, for example, increase the efficiency of disintegration of cell walls in yeast and thus improve the recovery of selenium by as much as 20 % [85]. 

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