Search results for "Chymotrypsin"
showing 7 items of 47 documents
Occurrence and Heterogeneity of Chymotrypsin Inhibitors in Vegetative Tissues of Barley
1977
Inhibitors of chymotrypsin and the alkaline proteinase of Aspergillus oryzae were present in the shoots of barley seedlings and weak activities were also detected in the shoot tops of 6-week-old plants. Treatments which induce inhibitor formation in tomato and potato leaves had no effect when tested on mature leaves, seedlings, or young tillers of barley. Fractionation experiments with isoelectric focusing showed that the barley leaves contained several proteinase inhibitors acting on both chymotrypsin and the Aspergillus proteinase, and one inhibitor which acted only on the Aspergillus enzyme. All of these inhibitors were different from the five Aspergillus proteinase inhibitors which are …
Preparative separation of proteins and enzymes in the mean molecular-weight range of 10,000–100,000 LiChrosorb diol® packing by high-performance size…
1979
Abstract LiChrossorb Diol® packing has been to be well-suited for the separation of proteins and enzymes according to a size-exclusion mechanism in a mean molecular-weight (MW) range between 10,000 and 100,000. Loadability of a small bore column of 6 mm I.D. (A) and a large-bore column of 23.5 mm I.D. (B), both of 250 mm in length, were examined. Defining a 20% decrease of the number of theoretical plates as loadability limit the volume load at constant mass of chymotrypsinogen as representative test solute was ≈ 100 μl for column (A) and 1500 μl for column B at 0.78 · 10-5 g/g of packing for column A and 0.78 · 10-6 g/g of packing for column B, respectively. Mass load to constant injection…
Inhibitors of endogenous proteinases in the seeds of Scots pine, Pinus sylvestris
1980
Extracts of resting pine seeds inhibited the proteinase activities present in extracts of endosperms of germinating seeds (hydrolysis of haemoglobin at pH 3.7 and hydrolysis of casein at pH 5.4 and 7.0). Heating the extracts of resting seeds at 60°C destroyed their own proteinase activity but their proteinase inhibitor activity decreased by only 25 to 30%. Some properties of the inhibitor(s) were studied using extracts treated at 60°C. The inhibitor activities were non-dialysable. the inhibition increased linearly with increasing inhibitor concentration up to 80% of total proteinase activity, and the maximal inhibition was 80% at pH 3.7. 90% at pH 5.4. and 97% at pH 7.0. The extracts of res…
Limited Proteolysis of Human α2-HS Glycoprotein/Fetuin
1996
alpha2-HS glycoprotein is a major protein of human plasma whose function is still obscure. A proteolytically processed form of alpha2-HS glycoprotein lacking a segment of 40 amino acid residues bridging its heavy and light chain portions ("connecting peptide") has been described suggesting that this peptide is released by post-translational processing to fulfill biological role(s) of alpha2-HS glycoprotein. To test this hypothesis we investigated how the connecting peptide is released from the parental molecule by limited proteolysis. We developed monoclonal antibodies to various portions of the connecting peptide and its NH2-terminal flanking region which cross-react with the native alpha2…
Analysis of Structure-Activity Relationships of the Bowman-Birk Inhibitor of Serine Proteinases
1993
Proteinase inhibitors are a class of the various dietary inhibitors of mutagenesis and carcinogenesis (Hayatsu et al., 1988). Schelp and Pongpaew (1988) have recently hypothesized that protection against cancer may result from an increase of endogenous proteinase inhibitors such as α2-macroglobulin induced by diets that are low in calories and fat. The Bowman-Birk inhibitor (BBI) of serine proteinases, a double-headed polypeptide-inhibitor of trypsin and chymotrypsin, is one of the most potent cancer chemopreventive agents (Yavelow et al., 1983, 1985). Recently, this property has been substantiated in an in vivo investigation using mice (St. Clair et al., 1990) that were exposed to dimethyl…
Crystal structure of the bifunctional soybean Bowman-Birk inhibitor at 0.28-nm resolution. Structural peculiarities in a folded protein conformation.
1996
The Bowman-Birk inhibitor from soybean is a small protein that contains a binary arrangement of trypsin-reactive and chymotrypsin-reactive subdomains. In this report, the crystal structure of this anticarcinogenic protein has been determined to 0.28-nm resolution by molecular replacement from crystals grown at neutral pH. The crystal structure differs from a previously determined NMR structure [Werner, M. H. & Wemmer, D. E. (1992) Biochemistry 31, 999-1010] in the relative orientation of the two enzyme-insertion loops, in some details of the main chain trace, in the presence of favourable contacts in the trypsin-insertion loop, and in the orientation of several amino acid side chains. The p…
Super-high-speed liquid chromatography of proteins and peptides on non-porous Micra NPS-RP packings
1999
Abstract The new generation of non-porous silica RP packings commercially available from Micra Scientific was tested for separations of peptides and proteins by means of the gradient HPLC. Extremely high-speed separations were achieved using conventional chromatographic equipment: six proteins could be completely separated within six seconds. Tryptic digest peptides could be resolved in more then 40 components within 2–3 min. The effect of the experimental parameters such as temperature, flow rate etc. was investigated.