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

Myoglobin isolated from red muscle of the gummy shark M. antarcticus was purified by gel filtration and ion-exchange chromatography on carboxymethyl cellulose in 8 M urea-thiol buffer. Amino acid analysis and sequence determination showed 148 amino acid residues. The amino terminal residue is acetylated as shown by nuclear magnetic resonance and mass spectrographic analysis of an N-terminal peptide. There is a deletion of four residues at the amino terminal end as well as one residue in the CD interhelical area relative to other myoglobins. These overall differences were also found previously in myoglobin of Heterodontus portusjacksoni. The complete amino acid sequence has been determined following digestion with trypsin, chymotrypsin, thermolysin, staphylococcal protease and cyanogen bromide. Sequences of purified peptides were determined by the dansyl-Edman procedure. The amino acid sequence showed approximately 88 differences from mammalian, monotreme, bird and tuna myoglobins, slightly more than previously reported for H. portusjacksoni usually considered a more primitive animal. There were 24 residues common to both shark myoglobins that were different from those present in other myoglobins. The sequence has been compared to the myoglobin of yellowfin tuna and other myoglobins.
 ...
PMID:Myoglobins of cartilaginous fishes. II. Isolation and amino acid sequence of myoglobin of the shark Mustelus antarcticus. 743 64

The complete primary structure of the major component myoglobin from the goose-beaked whale, Ziphius cavirostris, was determined by specific cleavage of the protein to obtain large peptides which are readily degraded by the automatic sequencer. Over 80% of the amino acid sequence was established from the three peptides resulting from the cleavage of the apomyoglobin at its two methionine residues with cyanogen bromide along with the four peptides resulting from the cleavage with trypsin of the citraconylated apomyoglobin at its three arginine residues. Further digestion of the central cyanogen bromide peptide with S. aureus strain V8 protease and the 1,2-cyclohexanedione-treated central cyanogen bromide peptide with trypsin enabled the determination of the remainder of the covalent structure. This myoglobin differs from the cetacean myoglobins determined to date at 12 to 17 positions. These large sequence differences reflect the distant taxonomic relationships between the goose-beaked whale and the other species of Cetacea the myoglobin sequences of which have previously been determined.
 ...
PMID:Complete amino acid sequence of the major component myoglobin from the goose-beaked whale, Ziphius cavirostris. 743 58

Addition of miscible organic solvents to water increases the solubility of naphthalene. The logarithm of the solubility is linearly dependent on the co-solvent concentration, in an intermediate range. The relative solubilising effects of different solvents correlate well with their known tendency to denature proteins (using literature data for trypsin, cytochrome c, chymotrypsinogen, chymotrypsin, laccase and myoglobin). This is expected if denaturation occurs when the hydrophobic effect has been reduced by a characteristic extent for a given protein. Naphthalene solubility predicts denaturation as well as does the denaturation capacity model.
 ...
PMID:Prediction of denaturing tendency of organic solvents in mixtures with water by measurement of naphthalene solubility. 754 59

Two 29-residue peptides were prepared, one of which (ChPepz) was designed by surface-simulation synthesis to mimic the active site of alpha-chymotrypsin, and the other (TrPepz), which contained four substitutions relative to ChPepz, was fashioned after the active site of trypsin. Each peptide was cyclized by a disulfide bond. The ChPepz monomer effected hydrolysis of the ester group in N-benzoyl-L-tyrosine ethyl ester, an alpha-chymotrypsin substrate, with Km and kcat values that were comparable to those of alpha-chymotrypsin. ChPepz was completely inactivated by diisopropyl fluorophosphate (DIFP), L-1-p-tosylamino-2-phenylethyl chloromethyl ketone (TPCK), or reduction of the disulfide bond. It had no catalytic activity on N-tosyl-L-arginine methyl ester, a trypsin substrate. On the other hand, TrPepz, which had no effect on N-benzoyl-L-tyrosine ethyl ester, hydrolyzed N-tosyl-L-arginine methyl ester with a Km value that was essentially identical to that of trypsin, but its kcat value was almost half that of trypsin. TrPepz was fully inactivated by reduction of the disulfide bond, by DIFP, or by phenylmethylsulfonyl fluoride but not by TPCK. It was also completely inhibited by soybean trypsin inhibitor, bovine pancreatic trypsin inhibitor, and human alpha 1-antitrypsin. ChPepz and TrPepz hydrolyzed proteins (myoglobin and casein) to give panels of peptides that were similar to those of the same protein obtained with the respective enzyme. However, TrPepz was more efficient than trypsin at hydrolyzing the C bonds of two or more consecutive lysine and/or arginine residues. Like its esterase activity, the proteolytic activity of ChPepz was inhibited by either DIFP or TPCK whereas that of TrPepz was inhibited by either DIFP or phenylmethylsulfonyl fluoride but not by TPCK. Finally, ChPepz and TrPepz were each more active at low temperature than the respective enzyme. This ability to construct fully functional peptide enzymes (pepzymes) of chosen specificities should find many practical applications.
 ...
PMID:Design of peptide enzymes (pepzymes): surface-simulation synthetic peptides that mimic the chymotrypsin and trypsin active sites exhibit the activity and specificity of the respective enzyme. 818 79

We report a case of acute pancreatitis with diabetic ketoacidosis associated with increased serum myoglobin concentration, acute renal failure, and disseminated intravascular coagulation. A 49-year-old man suffering from diarrhea, vomiting, and somnolence was admitted to the hospital. He had had flu-like symptoms for 4 days prior to the onset of these symptoms. He was a habitual drinker and had been consuming 360 ml-900 ml of the drink "shochu" (distilled spirits containing 28% alcohol) daily for 30 years. Laboratory data on admission revealed elevated serum levels of pancreatic enzymes, including amylase, trypsin, lipase, pancreatic secretory trypsin inhibitor (PSTI), phospholipase A2 (PLA2), and elastase-1, as well as elevated levels of glucose (373 mg/dl), ketone bodies (3675 mumol/l), and myoglobin (229.8 ng/ml). Treatment with subcutaneous insulin and intravenous administration of electrolyte fluid and the systemic protease inhibitor, gabexate mesilate, was begun immediately. Early after the initiation of treatment, there was an increase in serum creatinine (4.9 mg/dl), and thromobocytopenia (15000/microliters) was observed. The patient completely recovered from renal failure and acute pancreatitis, but required insulin therapy. Alcohol ingestion and dehydration are thought to have played a major role in the triggering of the acute pancreatitis. We examined the relationship among acute pancreatitis, diabetic ketoacidosis, and hypermyoglobinemia in the literature.
 ...
PMID:Acute pancreatitis with diabetic ketoacidosis associated with hypermyoglobinemia, acute renal failure, and DIC. 884 91

Rabbit antisera against human myoglobin and horse myoglobin cross-reacted with both myoglobins but only one of them recognized human hemoglobin. Two mouse monoclonal antibodies anti-human myoglobin were obtained, but only one of them (No. 49) cross-reacted with horse myoglobin. Antibody No. 49 and rabbit antibodies reacted also with apo-, FITC- and treated with hydrochloric acid or TPCK-trypsin horse myoglobin, but their binding to myoglobin pretreated with NaOH was reduced. Thirteen peptides overlapping sequence of human myoglobin were synthesized on polyethylene pins. Rabbit and mouse polyclonal antibodies reacted with some of these peptides but no reaction was noted with mouse monoclonal antibodies. Two monoclonal antibodies were applied for specific immunoassay of human myoglobin.
 ...
PMID:Antigenicity of human and horse myoglobins. 887 67

We show here that limited proteolysis can probe the structural and dynamic differences between the holo and apo form of horse myoglobin (Mb). Initial nicking of the polypeptide chain of apoMb (153 amino acid residues, no disulfide bonds) by several proteases (subtilisin, thermolysin, chymotrypsin and trypsin) occurs at the level of chain segment 89-96. In contrast, holoMb is resistant to proteolytic digestion when reacted under identical experimental conditions. Such selective proteolysis implies that the F-helix of native holoMb (residues 82 to 97) is disordered in apoMb, thus enabling binding and adaptation of this chain segment at the active site of the proteolytic enzymes for an efficient peptide bond fission. That essentially only the F-helix in apoMb is largely disrupted was earlier inferred from spectroscopic measurements and molecular dynamics simulations. The results of this study provide direct experimental evidence for this and emphasize therefore that limited proteolysis is a useful and reliable method for probing structure and dynamics of proteins, complementing other experimental techniques such as NMR and X-ray crystallography.
 ...
PMID:Probing the conformational state of apomyoglobin by limited proteolysis. 904 59

Water oxygen-17 and deuteron spin relaxation rates, measured as a function of resonance frequency, have been used to study the dynamics of protein hydration in aqueous solutions of ribonuclease A, lysozyme, myoglobin, trypsin and serum albumin. The relaxation data conform to the picture of protein hydration dynamics, proposed on the basis of previous studies of smaller proteins, where the long-lived water molecules responsible for the relaxation dispersion are identified with a small number of integrat water molecules seen in the crystal structures. These integral water molecules, with residence times in the range 10(-9)-10(-3) s, are either buried in internal cavities, trapped in narrow clefts or coordinated to metal ions. For the water molecules in the traditional hydration layer at the protein surface, the relaxation data suggest an average residence time in the range 10-50 ps, consistent with high-resolution 1H spectroscopy and computer simulations. The relaxation data also reveal some more specific features of protein hydration, relating to hydration of cavities that appear empty by crystallography, entrapment of water between structural domains of large proteins and subnanosecond 180 degrees flips in buried water clusters.
 ...
PMID:Protein hydration dynamics in aqueous solution. 913 39

For eleven films of various water-soluble alpha-, beta-, alpha-/beta-, and alpha-+beta-proteins, the amide-proton exchange, initiated by exposure of the protein film to 2H2O, has been monitored using infrared spectroscopy. The approach to obtain the kinetics of exchange for four different classes of amide protons, correlating to the different secondary structure types, has been described in detail in the preceding paper. In this work the more general applicability of the approach is illustrated by testing it for different types of proteins. The results obtained are shown not only to be comparable to reported time-resolved nuclear magnetic resonance data (as in the case of myoglobin, phospholipase A2, lysozyme, and cytochrome c), or to the more qualitative data obtained by neutron diffraction (trypsin, ribonuclease S, papain, and subtilisin BPN'), but the infrared approach us also provides with quantitative detailed insight on the distribution of exchange rate constants at the submolecular level of proteins, too complex to be studied by other techniques, as for tetrameric hemoglobin, and of proteins in which exchange is too fast to be detected by these other techniques, as is shown in this work for alpha-casein and apocytochrome c.
 ...
PMID:Amide-proton exchange of water-soluble proteins of different structural classes studied at the submolecular level by infrared spectroscopy. 935 29

In an earlier report (Litborn, E., Emmer, A., Roeraade, J., Anal. Chim. Acta 1999, 401, 11-19, we described a technique for performing chemistry in chip-based vials. A major problem, solvent evaporation, was partially remedied by using a closed humidity chamber. In this paper we report an improved technique for performing parallel reactions in open, 15 nL volume, chip-based vials. The evaporation of solvent from the reaction fluid was continuously compensated by addition of solvent via an array of microcapillaries. The suitability of the method was demonstrated by performing eight separate peptide maps of myoglobin in parallel, using the three enzymes trypsin, alpha-chymotrypsin and endoproteinase Glu-C. The total amount of myoglobin utilized to perform the eight digests was less than 100 pmol. The corresponding amount of enzymes was ca. 0.1 pmol per reaction. In order to evaluate the operating limits of the technique, a study of the evaporation of solvents from a series of vials with proportionally smaller volumes operated at different temperatures was performed. The results showed that the concept for continuous compensation of solvent evaporation should be applicable to reaction volumes down to 30 pL.
 ...
PMID:Parallel reactions in open chip-based nanovials with continuous compensation for solvent evaporation. 1063 74


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>