Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.16.2 (PCP)
 3,761 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The rise in serum myoglobin (MGB), total CPK (CKT) and its MB isoenzyme (CK - MB) was studied and compared over the first three days of acute myocardial infarction (AMI) and correlations were sought between the peak values of these three parameters and haemodynamic and biological indices of left ventricular function. Blood was taken from MGB (radio immunological technique), CKT and CK - MB (spectrophotometry) estimation every 2 hours for 24 hours and then every 6 hours up to the 72nd hour in 36 patients with AMI less than 12 hours old. On admission, this protocol was completed by a haemodynamic study (right heart pressures, systemic blood pressure, cardiac output measurement by thermodilution), arterial gases and ECG recordings. The average delays before the pathological rise, the maximal peak value and the return to normal were significantly shorter (p less than 0.001) for MGB (2, 6 and 25 hours) than for CK - MB (5,16 and 34 hours) or CKT (5,21 and 57 hours). The sensitivity of the diagnosis of myocardial infarction was not significantly higher with MGB than CKT or CK - MB either in the whole group (sensitivity of 91.6 p. 100 for MGB and 86.1 p. 100 for CKT and CK - MB) or in a subgroup of ten patients without transmural infarction (70 p. 100 for MGB compared with 60 p. 100 for CKT and CK - MB). A significant correlation was found between the peak values of MGB (p less than 0.02) and CK- MB (p less than 0.02) and the indices of left ventricular function (PCP, PAO2 and LVSWI). This was not observed with CKT. In conclusion, apart form technical problems which remain unresolved time-consuming investigation), serum MGB gives a much earlier and as sensitive a biochemical diagnosis of AMI as CKT and CK - MB. MGB and CK - MB are much better prognostic indicators than CKT as judged by the indices of left ventricular function. Finally, MGB estimation should be of particular value in the diagnosis of secondary extension of infarction.
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PMID:[Value of serum myoglobin in acute myocardial infarction. Kinetic study]. 679 24

The pressure dependence of the activity and spectroscopic properties of four carboxyl proteinases were investigated. Two were pepstatin-sensitive carboxyl proteinases (porcine pepsin and proteinase A from baker's yeast) and two were pepstatin-insensitive carboxyl proteinases (from Pseudomonas sp. 101 (pseudomonapepsin; PCP) and Xanthomonas sp. T-22 (xanthomonapepsin; XCP)). The specificity constant [k(cat)/K(m(app))] of PCP and XCP for a synthetic peptide substrate showed only a slight decrease with increasing pressure, whereas pepsin and proteinase A showed substantial disactivation at higher pressures. The calculated apparent activation volume (Delta V((k(cat)/(K(m)) was about 1, 3, 13, and 14 mL.mol(-1) for PCP, XCP, pepsin, and proteinase A, respectively. The hydrolysis of acid-denatured myoglobin by the four carboxyl proteinases was only slightly affected by high pressure (except for proteinase A at 400 MPa), in contrast to the results for the peptide hydrolysis. In fact, PCP, XCP, and proteinase A actually showed slightly higher degradations of acid-denatured myoglobin at higher pressures. The residual activities of these enzymes after the incubation at high pressures implied a pressure-induced stabilization towards autolysis. The changes in the fourth derivative near-UV absorbance spectrum of the four enzymes in aqueous solution were measured at various pressures from 0.1 to 400 MPa. Upon an increase in pressure, the peaks from PCP and XCP red-shifted slightly, whereas pepsin and proteinase A blue-shifted substantially, thus indicating a more polar environment. The intrinsic fluorescence also decreased upon increasing pressure. However, the change for XCP was rather small, but the change for the other three was very large. The changes in the peak wavelength for pepsin and proteinase A were characteristic, and also indicated a more polar environment under high pressure. An analysis by the center of spectra mass (CSM) gave the Delta G and Delta V of transition as 9.8 kJ x mol(-1) and -24 mL x mol(-1) (pepsin) and 11.7 kJ x mol(-1) and -43 mL x mol(-1) (proteinase A), respectively, by assuming a simple two-state transition. The circular dichroism (CD) showed relatively small changes after 1-h incubations at 400 MPa, indicating that the secondary structures were largely maintained.
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PMID:Effects of pressure on the activity and spectroscopic properties of carboxyl proteinases. Apparent correlation of pepstatin-insensitivity and pressure response. 1116 3

pH-Dependent kinetic parameters (k(on), k(off), and k(cat)) of protein (myoglobin) hydrolyses catalyzed by exo-enzyme (carboxypeptidase P, CPP) were obtained by using a protein-immobilized quartz crystal microbalance (QCM) in acidic aqueous solutions. The formation of the enzyme-substrate (ES) complex (k(on)), the decay of the ES complex (k(off)), and the formation of the product (k(cat)) could be analyzed by transient kinetics as mass changes on the QCM plate. The Kd (k(off)/k(on)) value was different from the Michaelis constant Km calculated from (k(off) + k(cat))/k(on) due to k(cat) > k(off). The rate-determining step was the binding step (k(on), and the catalytic rate k(cat) was faster than other k(on) and k(off) values. In the range of pH 2.5-5.0, values of k(on) gradually increased with decreasing pH showing a maximum at pH 3.7, values of k(off) were independent of pH, and k(cat) increased gradually with decreasing pH. As a result, the apparent rate constant (k(cat)/Km) showed a maximum at pH 3.7 and gradually increased with decreasing pH. The optimum pH at 3.7 of k(on) is explained by the optimum binding ability of CPP to the COOH terminus of the substrate with hydrogen bonds. The increase of k(cat) at the lower pH correlated with the decrease of alpha-helix contents of the myoglobin substrate on the QCM.
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PMID:Transient kinetic studies of pH-dependent hydrolyses by exo-type carboxypeptidase P on a 27-MHz quartz crystal microbalance. 1821 Oct 97