Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

From a crude extract of chick peas (Cicer arietinum L.) inhibitors of trypsin and chymotrypsin were isolated by affinity chromatography on a column of trypsin-Sepharose 6B. The content of inhibitors was found to be 1.5 g/kg. They were further separated into six isoinhibitors by ion-exchange chromatography on DEAE-Sephadex A-25. Two of the isoinhibitors accounted for about 50% of the isolated inhibitors and were further purified to a homogeneous state. The isoinhibitors had a molecular weight of about 10000 as determined by molecular-sieve chromatography on Sephadex G-75. They were stable towards extremes of pH and temperatures up to 75 degrees C or towards digestion by pepsin. They were also stable in 6 M urea but not in 6 M guanidine-HCl. The intact inhibitors were destroyed when the peas were cooked at 100 degrees C or when they were toasted at 130 degrees C. The four major inhibitors had similar amino acid compositions and did not contain detectable amounts of free sulfhydryl groups, tryptophan or carbohydrate. Cysteine is the dominant amino acid residue in all of them and accounted for about 20% of their amino acid content. The isoelectric point of the isoinhibitors lies in the range of pH 4.9-8.6 and two of the major inhibitors had isoelectric points of pH 4.75 and pH 4.96. They inhibited chymotrypsin to the same extent but differed in their inhibitory activities towards trypsin, indicating that they are mixtures of native and trypsinmodified forms and that they probably have separate sites for the two enzymes. They did not inhibit other proteolytic enzymes belonging to two groups (i.e., serine or cysteine enzymes) or originating from different sources (i.e., animals, plants or bacteria).
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PMID:The trypsin and chymotrypsin inhibitors in chick peas (Cicer arietinum L.). Purification and properties of the inhibitors. 0 Dec 66

This report describes macromolecules that bind (des-aspartic acid1)-angiotensin II, the des aspartic acid1 derivative of angiotensin I, and several biologically active and inactive analogues of these polypeptides. The macromolecules were found in the plasma of approximately 2 per cent of ambulatory adults and hospitalized children and 32 per cent of the patients at two institutions for the mentally retarded. The binding properties of these macromolecules were studied by incubating with peptides labeled with 125iodine, and separating bound from free labeled peptide using small gel filtration columns. The peptide-binding macromolecules from several patients were compared. They showed very similar specificity for a group of arginyl peptides of the des-aspartyl1-angiotensin sequence. The plasma binders differed from one another in their optimum pH and their mobility in electrophoretic fields. Those with more acid pH optima displayed more rapid electrophoretic mobility. The binders fell into two classes based on apparent molecular weight, approximately 140,000 and 250,000. Those with the higher apparent molecular weight contained a large proportion of binder that could be precipitated with antiserum to human IgA. Kinetic measurements showed that the plasma binders were somewhat heterogeneous with respect to affinity for (des-asp1)-angiotensin, with apparent association constants ranging from 10(7) to 10(8) M-1. Binding activity was labile to heat, and to treatment with pepsin or trypsin. It was inhibited by calcium, protamine, streptomycin, and some other cationic compounds. The plasma peptide binder differed in specificity and molecular weight from soluble angiotensin-binding molecules extracted from tissues, and from properties expected of a receptor for angiotensin. These macromolecules may be useful reagents for measuring (des-asp1)-angiotensins. Their presence in plasma samples may interfere with angiotensin assays in some circumstances.
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PMID:Peptide-binding macromolecules in the blood of seriously ill or mentally retarded patients. 0 55

Strains of transmissible gastroenteritis (TGE) virus possessing different pathogenicity were examined for stability to digestive enzymes and acid, and growth at various temperatures. In growth experiments, virus titer obtained at 37 degrees C were about equal between attenuated and virulent strains, but titers attained by the attenuated strain were higher at 30 degrees C. The attenuated virus multiplied at 28 degrees C, but the virulent virus did not at this temperature. The virulent virus was significantly stable to trypsin and pepsin, but the attenuated virus was inactivated rapidly by these proteolytic enzymes. No significant differences were observed in stability to acid between the attenuated and virulent strains. At different pH, both lost their infectivity more rapidly at 37 degrees C than at 22 degrees C.
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PMID:Comparison of properties between virulent and attenuated strains of transmissible gastroenteritis virus. 0 84

Polyethylene glycol (PEG) has been utilized to induce homokaryocyte formation in avian and mammalian erythrocytes previously treated with proteolytic enzymes. PEG of molecular weight 6,000-7,5000 was found superior to 1,500 and 20,000 MW PEG. Cells exposed to protease alone, prior to PEG treatment, fused to a high degree (60-95% multinucleated cells), whereas trypsin or pepsin treatment alone allowed very little fusion (2.5%). Trypsin lowered the effectiveness of protease when used in combination. Cells which were not treated with proteolytic enzymes agglutinated in the presence of PEG but did not fuse to a significant extent (0.01%). Fusion was also markedly dependent upon the rate at which PEG was eluted during the fusion process. Electron microscopy indicated that fusion began during the elution of PEG from the agglutinated cells.
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PMID:The fusion of erythrocytes by treatment with proteolytic enzymes and polyethylene glycol. 1 83

Several mucolytic agents were evaluated on sputum for testing their viscolytic activity and the bacterial tollerance to each of them. Proteolytic enzymes (trypsin, pepsin, papain, pancreatin), KJ, and dithiothreitol (or its derivatives) were better tollerated by common respiratory pathogens (H. influenzae, D. pneumoniae, Klebsiella, etc.) than other mucolytic agents, as acetil-cysteine, cisteamine-HCl, tension active substances, mercaptoethanol, and others. The dithiothreitol showed also one of the strongest viscolytic effect and therefore it was selected for the routinary sputum digestion at the concentration 0.1% in PBS pH 7.2. Such a solution was added to sputum specimen in different proportions according to the macroscopic "apparent" viscosity of each specimen. However researches on the comparative viscolytic activity of all the agents hereinafter considered are still in progress.
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PMID:[Study on the viscolytic activity of the sputum (author's transl)]. 1 42

Although the role of renin in hypertension continues to be incompletely defined, recent progress in the chemistry of renin has been considerable. Extensive purifications of hog kidney renin and the renin-like mouse submaxillary gland enzyme have been achieved. Various inhibitory peptides based on tetradecapeptide renin substrate have been useful in renin kinetic studies and in renin affinity chromatography. Classification of renin as an acid protease results from its marked inhibition by pepstatin and from the discovery that free carboxyl at the active site is essential for activity in human and hog kidney and mouse submaxillary gland enzymes. The presence of pseudorenin in all tissues has limited the use of model peptides as renin substrates in plasma and crude tissue extracts, since the proteolytic properties of the two enzymes are nearly identical. The existence of renin in multiple, chromatographically separable forms has been known. More recently inactive forms have been found in plasma, amniotic fluid, and hog and rabbit kidneys. Prolonged storage or treatment with acid, trypsin, or pepsin causes activation; in some instances the conversion is from a higher than normal molecular weight. The implications of these findings with respect to the renin-angiotensin system need much further investigation.
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PMID:New developments in our knowledge of the chemistry of renin. 1 50

Tosyl-triethylenetetramine-Sepharose (Tos-T-Sepharose) and carbenzoxytriethylenetetramine-Sepharose (Z-T-Sepharose) were found to be adsorbents utilizable in the purification of several microbial and animal proteases. The former Sepharose derivative adsorbed alpha-chymotrypsin, trypsin, subtilisin, thermolysin and neutral subtilopeptidase at neutral pH range, and acid proteases such as pepsin and Rhizopus niveus protease at pH 3.5-6.5. alpha-Chymotrypsin and trypsin were eluted with 0.1 N acetic acid and Rhizopus protease with 0.5 N acetic acid, thermolysin with 1 M guanidine-HCl or 33% ethyleneglycol, whilst pepsin was recovered by elution with 2 M guanidine-HCl at pH 3.5. The binding of neutral subtilopeptidase and subtilisin to this adsorbent was comparatively weak and both the enzymes were recovered by elution with 0.5 M NaCl at neutral pH. On the other hand, Z-T-Sepharose was found to bind tightly to these proteolytic enzymes except neutral subtilopeptidase. Trypsin and alpha-chymotrypsin were released from the adsorbent column with 1 M p-toluenesulfonate, and subtilisin with 1 M guanidine-HCl or 33% ethyleneglycol at neutral pH region. By these chromatographic procedures, the specific activities of these proteolytic enzymes increased effectively. Comparison of the binding abilities of acetyl-, benzoyl-, tosyl- and carbobenzoxy-T-Sepharoses to these enzymes suggests that hydrophobicity of tosyl and carbobenzoxy groups plays an important role in the enzyme-adsorbent interaction.
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PMID:Purification of several proteolytic enzymes by tosyl- and carbobenzoxy-triethylene-tetramine-sepharoses. 1 98

Myosin from rabbit stomach was highly purified by ammonium sulfate fractionation in the presence of ATP and MgCl2, ultracentrifugation and Sepharose 4B chromatography. The myosin composed of one heavy and two light chains as determined by SDS-gel electrophoresis. The molecular weights of the light chains were the same as those of gizzard myosin, about 20,000 and 17,000, respectively. The pH-activity curve and the KCl concentration dependency of Ca-ATPase of the stomach myosin were similar to those of other smooth muscle myosins. The stomach myosin was more resistant to pepsin digestion than skeletal myosin. Other proteolytic enzymes, trypsin, chymotrypsin, papain, and nagarse, digested the myosin in the same way as skeletal myosin.
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PMID:Purification and some properties of rabbit stomach myosin. 1 37

Soybean Bowman-Birk inhibitor, a double-headed inhibitor of trypsin and alpha-chymotrypsin, was treated with cyanogen bromide and then pepsin to yield two inhibitory active fragments. Structural investigation showed that one of the fragments was derived from the trypsin inhibitory domain and the other from the chymotrypsin inhibitory domain of the inhibitor. In contrast to the unusual stability of the native inhibitor, the separated domains were less stable and could be inactivated with excess proteinases. These results suggest that the legume double-headed inhibitors acquired their unusual stability by duplicating an ancestral single-headed structure.
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PMID:Studies on soybean trypsin inhibitors. XIII. Preparation and characterization of active fragments from Bowman-Birk proteinase inhibitor. 2 70

Encysted metacercariae of Zygocotyle lunata (Trematoda) excyst within 2 hr postexposure in the lower ileum of the domestic chick. Optimal in vitro excystation of this species occurs following pretreatment of the cyst for 15 min in 1% acidified pepsin, treatment in 0.02 M sodium dithionite (a reductant) for 1 to 2 min and then 2 hr treatment in an excystation medium containing 1% sodium glycocholate plus 1% trypsin in Earle's BSS adjusted to pH 8.8 with tris and maintained at 41 C. The cyst of this species is a dome-shaped hemisphere containing an inner and outer wall. The outer wall contains mainly acid mucopolysaccharides, whereas the inner wall is mainly proteinaceous. The cyst contains a ventral lid which only was visualized during excystation.
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PMID:In vivo and in vitro excystation of Zygocotyle lunata (Trematoda) metacercariae and histochemical observations on the cyst. 2 36


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