Proteins proteinase inhibitors

Protein Proteinase Inhibitors—Molecular Aspects Michael Laskowski, Jr. and Robert W. Sealock... 

The conformational flexible part found in domain II of SSI is in stark contrast with other protein proteinase inhibitors, such as BPTI. In the case of BPTI, the backbone conformation is found to be nearly identical in both the free and the bovine trypsin complex.28 The conformational rigidity of protein proteinase inhibitors has been considered for a long time to be a necessary condition to inhibit their target enzymes and to protect themselves from attack by other proteinases. It is generally recognized that the substrate-like protein proteinase inhibitors, such as BPTI, STI, and Ovomucoid domain 3,... 

We have shown above, although in a very qualitative way, that various NMR evidence seems to indicate that two peculiar features of SSI, namely dimeric structure and wide inhibitory activity, which are rather unusual for protein proteinase inhibitors, are actually closely related. The molecular assembly of the SSI subunit can be conceptually divided into two subdomains having a similar topology domain I, which is located at the N-... 

Bode W, Huber R. Natural protein proteinase inhibitors and their interaction with proteinases. Eur. J. Biochem. 1992 204 433-451. 

Human antitlirombin, a member of the serpin family of protein proteinase inhibitors, contains four tryptophan residues (Fig. 7.3) that belong to two classes, buried and solvent exposed. Fluorescence lifetime measurements of wild type protein and of four variants containing single Trp Phe mutations, allow obtaining for each protein three lifetimes, 0.23 + 0.04, 1.6 + 0.13 and 6 + 0.9 ns. 

Uehara, Y., Tonomura, B., and Hiromi, K. (1978). Direct fluoro-metric determination of a dissociation constant as low as 10 0 M for the subtilisin BPN —protein proteinase inhibitor (StrepTotnyces subtilisin inhibitor) complex by a single photon counting technique. J. Biochem. (Tokyo) 84, 1195-1202. 

Antinutritive substances, e. g., allergenic proteins, proteinase inhibitors, lectins and cyanogenic glycosides, are found in food raw materials. These substances will be described in this chapter since a large variety have been identified in legumes. 

Ozaki, N., Ohmuraya, M., Hirota, M. (2009). Serine protease inhibitor Kazal typ>e 1 ptromotes proliferation of pancreatic cancer cells through the epidermal growth factor receptor. Mol Cancer. Res., Vol. 7, pp. 1572-1581, ISSN 1557-3125 Polya, G.M. (2003). Protein and non-protein proteinase inhibitors from plants. In Bioactive natural products, Ed. by Atta-ur- Rahinan, Vol. 29, Part 1, p>p. 567-641, Elsevier, ISBN 978-0-444-53181-0, Netherlands... 

Hansson T and J Aqvist 1995. Estimation of Binding Free Energies for HIV Proteinase Inhibitors b Molecular Dynamics Simulations. Protein Engineering 8 1137-1144. 

Protein acidulant Protein additives Protein ammo acids a-l-Proteinase inhibitor Protein-based mimetics Protein Ca [42617-41-4] Protein channels Protein chromatography Protein crystal growth... 

Factor VIII, immunoglobulin, and albumin are all held as protein precipitates, the first as cryoprecipitate and the others as the Cohn fractions FI + II + III (or FII + III) and FIV + V (or FV), respectively (Table 7, Fig. 2). Similarly, Fractions FIVj + FIV can provide an intermediate product for the preparation of antithrombin III and a-1-proteinase inhibitor. This abiUty to reduce plasma to a number of compact, stable, intermediate products, together with the bacteriacidal properties of cold-ethanol, are the principal reasons these methods are stiU used industrially. 

Alpha-1-proteinase inhibitor and antithrombin III are used to treat people with hereditary deficiencies of these proteins. Both can be recovered from Cohn Fraction IV (Table 7) using ion-exchange chromatography (52) and affinity chromatography (197), respectively. Some manufacturers recover antithrombin III directiy from the plasma stream by affinity adsorption (56,198,199). 

ACTH, adrenocorticotrophic hormone Met, methionine Met(O), methionine sulfoxide DTT, dithiothreitol L7, L12, Escherichia coli ribosomal proteins Met(0)-L12, L12 containing Met(O) residues a-l-PI, a-1-proteinase inhibitor Met(0)-a-l-PI, a-l-PI... 

Other plasminogen activator inhibitors are PAI-3, which is believed to be identical to the activated protein C inhibitor, and proteinase nexin 1, found in the renal epithelial cells, cytosol of fibroblasts, and cardiac myocytes (37, 42, 44, 45). 

In this laboratory, we also include the metal ion chelators EDTA (ethylene diamine tetraacetic acid binds, e.g., Mg2 1 -ions) and EGTA (ethylene glycol-bis(2-aminoethyl)-Al,iV,iV/,iV/,-tetraacetic acid binds, e.g., Ca2+-ions) in our lysis buffers. These agents help prevent phosphatase action (by the metal ion-dependent phosphatase PP2C, which is not inhibited by microcystin-LR), metal (Ca2+) dependent proteinases, and protein kinases, which require divalent cations such as Mg2 1 (and, in some cases, also Ca2+). We also use a mix of proteinase inhibitors that inhibit a broad range of proteolytic enzymes, including serine and cysteine proteinases. 

The first hurdle encountered during the development of alfalfa as a recombinant protein production system was the relative inefficiency of the available expression cassettes. A study in which a tomato proteinase inhibitor I transgene was expressed in tobacco and alfalfa under the control of the cauliflower mosaic virus (CaMV) 35S promoter showed that 3-4 times more protein accumulated in tobacco leaves compared to alfalfa leaves [5]. Despite the low efficiency of the CaMV 35S promoter in alfalfa, bio-pharmaceutical production using this system has been reported in the scientific literature. Such reports include expression of the foot and mouth disease virus antigen [6], an enzyme to improve phosphorus utilization [7] and the anti-human IgG C5-1 [8]. In this last work, the C5-1 antibody accumulated to 1% total soluble protein [8]. 

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