Trypsin production inhibition

Proteinases and antiproteinases are part of the normal protective and repair mechanisms in the lungs. The imbalance of proteinase-antiproteinase activity in COPD is a result of either increased production or activity of destructive proteinases or inactivation or reduced production of protective antiproteinases. AAT (an antiproteinase) inhibits trypsin, elastase, and several other proteolytic enzymes. Deficiency of AAT results in unopposed proteinase activity, which promotes destruction of alveolar walls and lung parenchyma, leading to emphysema. 

Ricin is a potent cellular protein toxin contained in the beans of the castor been plant (Ricinus communis), which is extensively cultivated for oil production and is also a common ornamental garden plant. Ricin is able to inhibit ribosomal protein synthesis eventually causing cell death, and owing to these properties it has been allegedly used in terrorist and criminal activities. After trypsin digestion of castor bean crude extracts, Ostin et al. [105] were able to unambiguously... 

For enzyme inhibition assays, urine is the preferred specimen [4]. Interestingly, Bik can be measured by the inhibition of trypsin in urine but not in plasma. Urinary Bik analysis may also be performed by antibody staining, latex agglutination, and radioimmunoassay (RIA) [4]. Despite the analytical approach used, all Bik forms are measured together. The enzyme inhibition method involves adding known amounts of trypsin to the specimen and monitoring trypsin inhibition. Trypsin activity is assessed by detection of by-products from a cleavable substrate. Dipstick methods are available for the rapid detection of trypsin inhibitors in urine [15, 17 19]. 

The exact form in which non-crosslinked elastin is secreted from smooth muscle cells is yet to be clearly defined. Foster et al. (36) have suggested that a non-cross linked elastin (pro-elastin) is secreted from smooth muscle cells in a form that is approximately 120,000 to 140,000 daltons. They have suggested that proelastin is cleaved to smaller molecular weight forms of non-crosslinked elastin. It should be noted, however, that this view is not entirely supported by data from other laboratories. There are two reports on the use of isolated mRNA from chick aorta suggesting only a 70,000 dalton non-cross linked elastin is the major product of translation (37,38). There is also a recent report suggesting that aortic mRMA translates a 200,000 dalton putative elastin product (39). We have recently isolated a non-crosslinked elastin from the aortas of copper deficient chicks that appears to be 100,000 daltons (27). Its amino acid composition is similar to that for tropoelastin (Table III). A major problem in resolving these points is that the trypsin-like proteinase associated with elastin is not easily denatured or separated from the non-crosslinked forms of elastin. The proteinase is also not readily inhibited by commonly used inhibitors for trypsin-like proteinases (26). 

Indicator variables (/) are often used to highlight a structural feature present in some of the molecules in a data set that confers unusual activity or lack of it to these particular members. Their use could be beneficial in cases where the data set is heterogeneous and includes large numbers of members with unusual features that may or may not impact a biological response. QSAR for the inhibition of trypsin by X-benzamidines used indicator variables to denote the presence of unusual features such as positional isomers and vinyl/ carbonyl-containing substituents (170). A recent study on the inhibition of lipoxygenase catalyzed production of leukotriene B4 and 5-hydroxyeicosatetraenoic from arachidonic... 

Using trypsinogen as biocatalyst under similar conditions in the dropping experiment, after 400 min analytical HPLC showed 21% of 26 and 79% of 25. The conversion of the acyl donor ester was only 80%. Preparative RP-HPLC provided 26 yield Img (7%). The determined amino acid composition corresponded with the calculated values. In the appropriate batch experiment the analytical yield was 17% of 26 (95% conversion of 24), whereas the application of trypsinogen inhibited by basic pancreatic trypsin inhibitor provided only 8% of 26 after 24 h at 48% conversion of the acyl donor ester 24. Using trypsin instead of the zymogen, after approximately 20 min, more than 50% of 26 (after Imin, 20% product formation at 100% conversion of 24) and 25 were digested. 

---