Low serum potassium concentration is a predictor of chronic kidney disease.

AIMS: The aim of this study was to examine whether low serum potassium concentration could be a predictor of chronic kidney disease (CKD) in a community-based cohort. MATERIALS AND METHODS: We enrolled 1001 subjects, median period of 5.7 years, and evaluated the risk factors for CKD, defined as estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m(2), and assessed whether low serum potassium concentration could predict CKD. RESULTS: Compared with the subjects without development of CKD, age, body mass index, fasting plasma glucose, uric acid (UA), creatinine and serum sodium concentration were higher, and serum potassium concentration was lower in subjects with development of CKD. Univariate Cox regression analyses demonstrated that age, body mass index, fasting plasma glucose, UA, creatinine, serum sodium concentration and serum potassium concentration were associated with progression of CKD. Multiple Cox regression analysis revealed that age, gender, creatinine and serum potassium concentration were independent predictors of CKD after adjustment for covariates. When serum potassium concentration was below 4.0 mmol/l at baseline, hazard ratio (95% confidence interval) of developing CKD was 2.65 (2.04-3.44; p < 0.0001). CONCLUSIONS: Serum potassium concentration could be a clinically relevant risk factor for the progression of CKD, defined as eGFR < 60 ml/min/1.73 m(2) , in healthy subjects.

Andropausal symptoms in men with Type 2 diabetes.

AIMS: Serum androgen concentration is reported to be low in patients with Type 2 diabetes. There have been no studies comparing andropausal symptoms such as sleep disturbance, depression, erectile dysfunction and lower urinary tract symptoms simultaneously between men with Type 2 diabetes and subjects without diabetes. METHODS: We compared andropausal symptom scores such as the Pittsburgh Sleep Quality Index, the Self-Rating Depression Scale, the International Index of Erectile Function and the International Prostate Symptom Score in 296 men with Type 2 diabetes and in 267 subjects without diabetes. Furthermore, we evaluated relationships of andropausal symptom scores to various anthropometric factors and compared andropausal symptom scores according to diabetic complications in men with Type 2 diabetes. RESULTS: Andropausal symptom scores such as the Pittsburgh Sleep Quality Index, the Self-Rating Depression Scale, the International Index of Erectile Function and the International Prostate Symptom Score were 4.2 ± 2.6 vs. 5.0 ± 3.3, P<0.01 by unpaired Student's t-test, 34.8 ± 8.2 vs. 38.4 ± 9.3, P<0.0001, 11.5 ± 6.4 vs. 9.9 ± 6.9, P<0.01 and 7.3 ± 6.7 vs. 9.0 ± 7.1, P<0.01 in subjects without diabetes and in patients with diabetes, respectively. The Pittsburgh Sleep Quality Index was higher in patients with neuropathy than without. The Self-Rating Depression Scale was higher in patients with advanced retinopathy. The International Index of Erectile Function was lower in patients with advanced retinopathy and nephropathy. The International Index of Erectile Function was lower and the International Prostate Symptom Score was higher in patients with cardiovascular disease than without. CONCLUSIONS: Our data demonstrated that men with Type 2 diabetes have higher prevalence of andropausal symptoms, especially those with diabetic complications.

High-power laser experiment forming a supercritical collisionless shock in a magnetized uniform plasma at rest.

We present an experimental method to generate quasiperpendicular supercritical magnetized collisionless shocks. In our experiment, ambient nitrogen (N) plasma is at rest and well magnetized, and it has uniform mass density. The plasma is pushed by laser-driven ablation aluminum (Al) plasma. Streaked optical pyrometry and spatially resolved laser collective Thomson scattering clarify structures of plasma density and temperatures, which are compared with one-dimensional particle-in-cell simulations. It is indicated that just after the laser irradiation, the Al plasma is magnetized by a self-generated Biermann battery field, and the plasma slaps the incident N plasma. The compressed external field in the N plasma reflects N ions, leading to counterstreaming magnetized N flows. Namely, we identify the edge of the reflected N ions. Such interacting plasmas form a magnetized collisionless shock.

Efficient delivery of liposome-mediated MGMT-siRNA reinforces the cytotoxity of temozolomide in GBM-initiating cells.

Glioblastoma multiforme (GBM) is one of the most formidable brain tumors with a mean survival period of approximately 12 months. To date, a combination of radiotherapy and chemotherapy with an oral alkylating agent, temozolomide (TMZ), has been used as first-line therapy for glioma. However, the efficacy of chemotherapy for treating GBM is very limited; this is partly because of the high activity levels of the DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) in tumor cells, which creates a resistant phenotype by blunting the therapeutic effect of alkylating agents. Thus, MGMT may be an important determinant of treatment failure and should be considered as a suitable target for intervention, in an effort to improve the therapeutic efficacy of TMZ. In this study, we showed that small-interfering RNA (siRNA)-based downregulation of MGMT could enhance the chemosensitivity of malignant gliomas against TMZ. Notably, TMZ-resistant glioma-initiating cells with increased DNA repair and drug efflux capabilities could be efficiently transduced with MGMT-siRNA by using a novel liposome, LipoTrust. Accordingly, such transduced glioma-initiating cells could be sensitized to TMZ in both in vitro and in vivo tumor models. Taken together, this study provides an experimental basis for the clinical use of such therapeutic combinations.

Nuclear DISC1 regulates CRE-mediated gene transcription and sleep homeostasis in the fruit fly.

Disrupted-in-schizophrenia-1 (DISC1) is one of major susceptibility factors for a wide range of mental illnesses, including schizophrenia, bipolar disorder, major depression and autism spectrum conditions. DISC1 is located in several subcellular domains, such as the centrosome and the nucleus, and interacts with various proteins, including NudE-like (NUDEL/NDEL1) and activating transcription factor 4 (ATF4)/CREB2. Nevertheless, a role for DISC1 in vivo remains to be elucidated. Therefore, we have generated a Drosophila model for examining normal functions of DISC1 in living organisms. DISC1 transgenic flies with preferential accumulation of exogenous human DISC1 in the nucleus display disturbance in sleep homeostasis, which has been reportedly associated with CREB signaling/CRE-mediated gene transcription. Thus, in mammalian cells, we characterized nuclear DISC1, and identified a subset of nuclear DISC1 that colocalizes with the promyelocytic leukemia (PML) bodies, a nuclear compartment for gene transcription. Furthermore, we identified three functional cis-elements that regulate the nuclear localization of DISC1. We also report that DISC1 interacts with ATF4/CREB2 and a corepressor N-CoR, modulating CRE-mediated gene transcription.

Relationship Between Stress Coping Mechanisms and Depression in Kidney Transplant Recipients.

BACKGROUND: It has been reported that transplant recipients are exposed to physical and psychosocial stresses even after transplant surgery and exhibit psychological disorders such as depression. PURPOSE: In this study, we extracted trends concerning how recipients of kidney transplants cope with stress, and we also examined how they cope with depression and its countermeasures. METHOD: We administered questionnaire surveys to 109 kidney transplant recipients. These included items on personal attributes, medical information, depression, and stress-coping type scales. Statistical analysis was performed using factor analysis and multiple regression analysis. RESULTS: Fifteen out of 109 (13.8%) were found to be high-risk patients for depression based on responses to the questionnaire using the depression scale. We extracted 2 factors of stress-coping type, namely Factor 1, "Directly coping with the problem," of patients who try to directly resolve the problem in a positive manner and Factor 2, "Stress-release while avoiding the problem," for those who relieve their feelings in response to the stress without resolving the problem itself. When multiple regression analysis was conducted with the depression scale as the dependent variable and the stress-coping factor as the independent variable, Factor 1 tended to be associated with reduced depression and Factor 2 with increased depression. CONCLUSIONS: Results showed that to improve the mental health of those who receive kidney transplants, it is necessary to examine the depression and stress-coping types of such patients at an early stage and carry out education on stress-coping, focusing on resolving the actual problem.

Stimulatory action of protein kinase C(epsilon) isoform on the slow component of delayed rectifier K+ current in guinea-pig atrial myocytes.

BACKGROUND AND PURPOSE: Protein kinase C (PKC) comprises at least twelve isoforms and has an isoform-specific action on cardiac electrical activity. The slow component of delayed rectifier K(+) current (I (Ks)) is one of the major repolarizing currents in the hearts of many species and is also potentiated by PKC activation. Little is known, however, about PKC isoform(s) functionally involved in the potentiation of I (Ks) in native cardiac myocytes. EXPERIMENTAL APPROACH: I (Ks) was recorded from guinea-pig atrial myocytes, using the whole-cell configuration of patch-clamp method. KEY RESULTS: Bath application of phenylephrine enhanced I (Ks) concentration-dependently with EC(50) of 5.4 microM and the maximal response (97.1+/-11.9% increase, n=16) was obtained at 30 microM. Prazosin (1 microM) almost totally abolished the potentiation of I (Ks) by phenylephrine, supporting the involvement of alpha(1)-adrenoceptors. The stimulatory action of phenylephrine was significantly, if not entirely, inhibited by the general PKC inhibitor bisindolylmaleimide I but was little affected by Gö-6976, Gö-6983 and rottlerin. Furthermore, this stimulatory effect was significantly reduced by dialyzing atrial myocytes with PKCepsilon-selective inhibitory peptide epsilonV1-2 but was not significantly affected by conventional PKC isoform-selective inhibitory peptide betaC2-4. Phorbol 12-myristate 13-acetate (PMA) at 100 nM substantially increased I (Ks) by 64.2+/-1.3% (n=6), which was also significantly attenuated by an internal dialysis with epsilonV1-2 but not with betaC2-4. CONCLUSIONS AND IMPLICATIONS: The present study provides experimental evidence to suggest that, in native guinea-pig cardiac myocytes, activation of PKC contributes to alpha(1)-adrenoceptor-mediated potentiation of I (Ks) and that epsilon is the isoform predominantly involved in this PKC action.

Girdin maintains the stemness of glioblastoma stem cells.

This corrects the article DOI: 10.1038/onc.2011.466.

High-speed gas sensor for chemosensory event-related potentials or magnetic fields.

The observation of odor and air exchange with high temporal accuracy is necessary to obtain strict chemosensory event-related potentials (CSERPs) or magnetic fields, as proposed by Evans et al. [Evans W, Kobal G, Lorig T, Prah J. Suggestions for collection and reporting of chemosensory (olfactory) event-related potentials. Chem Senses, 1993; 18: 751- 6]. No suitable method for real time observation of gas stimuli, however, has been available until now. We have developed a technique to measure accurately gas molecule concentrations with a high temporal resolution. We determined that attenuation of sound amplitude varies in a manner dependent on the average molecular weight through which the sound wave passes. Based on this principle, we have designed a high-speed gas concentration sensor utilizing ultrasound. We investigated the practical potential of this sensor using a chemosensory stimulator (olfactometer); we succeeded in observing rapid gas exchange between air and nitrogen with a 2 kHz sampling rate. The signal/noise ratio of the stimulus was greater than 42 dB. In a 20 min experiment we determined that, for this olfactometer, the gas onset latency was 79 ms and the rise time was 16 ms. No significant artifact to magnetic fields was observed, even when the sensor was situated near a whole head magnetoencephalography (MEG) system. These results indicate that this sensor could be used for the observation of odor and air exchange, as well as, for real time monitoring of odor stimuli during actual experiments with a participant.

Isolation and characterization of Taka-amylase A apoprotein deglycosylated by digestion with almond glycopeptidase immobilized on Sepharose.

Taka-amylase A (1,4-alpha-D-glucan glucanohydrolase, EC 3.2.1.1), which contains a single asparagine-linked oligosaccharide unit, was digested with almond glycopeptidase immobilized on Sepharose 6B at 20 degrees C for 4 h. A maximum of 10% of the parent protein was isolated as apoprotein by column chromatography on Con-A Sepharose. The characteristics of the apoprotein were compared to those of the native Taka-amylase A. The removal of the sugar chain from Taka-amylase. A caused no change in the pH-activity profile or in kinetic parameters of the hydrolysis of soluble starch. The stability of the apoprotein toward changing pH and digestion by proteases did not show any appreciable difference from that of the native Taka-amylase. These results suggest that the carbohydrate moiety of Taka-amylase A is not an essential participant in the catalysis.

Early assessment of reperfusion therapy using cardiac troponin T.

OBJECTIVES: The purpose of this study was to investigate the utility of cardiac troponin T for early assessment of reperfusion therapy. BACKGROUND: Several biochemical markers are used for early noninvasive detection of reperfusion during intravenous thrombolytic therapy. However, cardiac troponin T, a new myocardial-specific marker, has not been used previously for this purpose. METHODS: We measured troponin T and creatine kinase, MB isoenzyme (CK-MB) levels in 38 patients with acute myocardial infarction whose infarct-related artery was totally occluded before reperfusion therapy. Subjects comprised 14 patients with successful angioplasty (group 1), 12 patients with successful thrombolytic therapy (group 2) and 12 patients with unsuccessful attempted reperfusion (group 3). Blood samples were taken every 15 min, and coronary angiography was performed every 5 to 8 min until 60 min after reperfusion (groups 1 and 2) or after the initiation of treatment (group 3). We calculated the increase in troponin T (delta troponin T) and CK-MB (delta CK-MB) 60 min after treatment was initiated and 60 min after reperfusion in groups 1 and 2. RESULTS: Mean (+/- SD) delta troponin T and delta CK-MB levels were 9.35 +/- 7.83 ng/ml and 125 +/- 83 mU/ml in group 1 and 3.23 +/- 3.08 ng/ml and 130 +/- 137 mU/ml in group 2, respectively, 60 min after treatment and were 10.1 +/- 8.35 ng/ml and 131 +/- 84 mU/ml in group 1 and 6.84 +/- 8.30 ng/ml and 158 +/- 146 mU/ml in group 2, respectively, 60 min after reperfusion. These values were significantly higher than those 60 min after treatment in group 3: 0.16 +/- 0.19 ng/ml and 10 +/- 9 mU/ml, respectively. The predictive accuracy for detecting reperfusion using a threshold value of 0.50 ng/ml of delta troponin T and 25 mU/ml of delta CK-MB was 100% in group 1 and 92% in group 2 60 min after treatment, respectively. There was significant correlation between delta troponin T and delta CK-MB. CONCLUSIONS: Serial measurements of cardiac troponin T as well as of CK-MB are useful for early assessment of reperfusion therapy.

Rapid diagnosis of coronary reperfusion by measurement of myoglobin level every 15 min in acute myocardial infarction.

OBJECTIVES: The purpose of this study was to examine whether coronary reperfusion can be diagnosed rapidly and accurately by myoglobin measurements. BACKGROUND: When intravenous thrombolysis is used for acute myocardial infarction, it is important to determine coronary reperfusion rapidly and noninvasively so that further treatment can be initiated. METHODS: We determined myoglobin, creatine kinase (CK) and creatine kinase, MB fraction (CK-MB) isoenzyme levels in 63 patients with acute myocardial infarction with total occlusion of the infarct-related artery that was confirmed by coronary angiography. Myoglobin was measured by turbidimetric latex agglutination, which has an assay time of 10 min. We measured myoglobin, CK and CK-MB every 15 min in 45 patients with and 18 patients without reperfusion. The condition of the infarct-related artery was confirmed every 5 to 8 min by coronary angiography. RESULTS: The rate of increase in myoglobin, CK, and CK-MB at 15, 30, 45 and 60 min after treatment and reperfusion was significantly higher in the reperfused than in the nonreperfused group. In the reperfused group, the rate of increase in myoglobin was significantly higher than the corresponding rate of increase in CK and CK-MB at 15, 30 and 45 min after reperfusion. When reperfusion was evaluated on the basis of a cutoff level (myoglobin > or = 2.0, CK > or = 1.8, CK-MB > or = 1.5), the predictive accuracy of myoglobin (95%) was significantly higher than that of CK (68%) and CK-MB (73%) at 15 min after reperfusion. CONCLUSIONS: Coronary reperfusion can be rapidly and accurately detected by measurement of the plasma myoglobin every 15 min.

Protease inhibitors (gebexate mesylate and ulinastatin) stimulate intracellular chemiluminescence in human neutrophils.

The effect of protease inhibitors on the intracellular production of free radicals was investigated by measuring chemiluminescence (CL) elicited from phagocytosed luminol-bound microspheres (Lumispheres) in human neutrophils stimulated with formylmethionyl-leucyl-phenylalanine (fMLP), interleukin-8 (IL-8), phorbol 12-myristate 13-acetate, or diacylglycerol. Both gabexate mesylate (Foy) and ulinastatin (Miraclid), urinary trypsin inhibitor, increased intracellular CL in a dose dependent manner. Compared to control buffer without protease inhibitor, gabexate mesylate (322 micrograms/ml) caused about a 10-fold increase in intracellular CL in stimulated neutrophils, and ulinastatin (3100 U/ml) a twofold increase in neutrophils stimulated with fMLP or IL-8. When the protease inhibitors were added to the cell suspension after the phagocytosis of lumispheres, CL responses rapidly increased again to the level which was observed when both protease inhibitors and neutrophil stimulants were incubated simultaneously. In contrast, extracellular release of oxygen metabolites from stimulated neutrophils, assayed by a conventional measurement of luminol-dependent CL, was reduced by the protease inhibitors in a dose dependent fashion. When luminol-unbound microspheres were incubated with neutrophils stimulated by fMLP in luminol solution, extracellular CL was almost completely inhibited by gabexate mesylate. These results indicate that the protease inhibitors enhance the generation of intracellular CL and suppress the extracellular release of free radicals.

Right ventricular stiffness measured by a new method without volume estimation in coronary artery disease.

This study was designed to measure the right ventricular (RV) stiffness (delta P/ delta V) with a new method without estimating the RV volume itself. RV stiffness has rarely been measured due to the difficulty in estimating the RV volume. Without measuring RV volume itself, stiffness can be determined by measuring its volume change (delta V). Tricuspid filling flow volume, which is the diastolic RV delta V, is measurable by using Doppler echocardiography. Thus, RV stiffness may possibly be obtained from Doppler echocardiography combined with high-fidelity RV pressure. Subjects consisted of 8 controls, 8 patients with angina pectoris, 8 with anterior, 8 with posterior, and 8 with inferior prior myocardial infarction. Tricuspid annular dimension was measured by 2-dimensional echocardiography and the tricuspid annular area was calculated. Velocity-time integral of the tricuspid filling flow during the late diastole was measured by pulsed Doppler echocardiography. Then, the late diastolic RV delta V was obtained as the product of the tricuspid annular area and the integral. The late diastolic RV pressure rise (delta P) was also measured with a micromanometer catheter. The RV elastic chamber stiffness constant ([delta P/ delta V]/P) was obtained by dividing simple stiffness by the mean RV pressure during late diastole. The RV elastic chamber stiffness constant did not significantly differ among controls, patients with angina pectoris, and those with anterior and posterior myocardial infarction (0.0054 +/- 0.0009 vs 0.0057 +/- 0.0018 vs 0.0064 +/- 0.002 vs 0.0052 +/- 0.0019 ml-1). However, it was significantly increased in patients with inferior myocardial infarction (0.010 +/- 0.004 ml-1, p < 0.01 or 0.05) compared with those in the other 4 groups. These results suggest (1) that RV stiffness can be measured with a new method without RV volume estimation, and (2) that this new method is useful in evaluating RV diastolic pathophysiology in patients with coronary artery disease.

Influence of left ventricular filling profile on the effect of atrioventricular synchronous pacing.

We correlated the percentage of atrial contribution to left ventricular filling (percent AC) assessed by Doppler echocardiography with the hemodynamic benefit from atrioventricular synchronous pacing assessed by direct hemodynamic measurements. Subjects comprised 40 patients who underwent electrophysiologic catheterization because of unexplained syncope or bradycardia (< 40 beats/min). Femoral arterial and pulmonary capillary wedge pressure were recorded by catheterization, and cardiac output was measured by thermodilution during temporary atrioventricular synchronous (DDD, 70 beats/min with 150 ms of atrioventricular delay) and ventricular (VVI, 70 beats/min) pacing. Mitral inflow velocity by pulsed-wave Doppler echocardiography was recorded during DDD pacing and percent AC was obtained by calculating the ratio of mitral inflow velocity area during atrial systole to total mitral inflow velocity area during early diastole and atrial systole. The mean arterial pressure and the cardiac output increased significantly (99 +/- 16 mm Hg vs 90 +/- 15 mm Hg, p < 0.001; 4.6 +/- 1.0 L/min vs 3.9 +/- 0.9 L/min, p < 0.001), and the mean pulmonary capillary wedge pressure decreased (7 +/- 4 mm Hg vs 10 +/- 4 mm Hg, p < 0.001) during DDD compared with VVI pacing. A significant positive correlation was observed between the percent AC and the increase in cardiac output (r = 0.58, n = 40, p < 0.01) or the increase in mean arterial pressure (r = 0.62, n = 38, p < 0.01) during DDD pacing. The percent AC did not significantly correlate with the decrease in pulmonary capillary wedge pressure. In conclusion, patients with larger percent AC may receive major benefit from atrioventricular synchronous pacing.

Roles of the lateral suprasylvian cortex in convergence eye movement in cats.

Ocular convergence and lens accomodation were evoked by microstimulation in the lateral suprasylvian area (LS cortex) in the parieto-occipital cortex in the cat. Electrolytic lesions in LS cortex reduced the amplitude and velocity of ocular convergence. Neurons in LS cortex discharged in relation to ocular convergence and/or lens accommodation. These results support the hypothesis that the LS cortex plays an important role in controlling ocular convergence The LS cortex receives visual inputs from cortical visual areas 17, 18 and 19, and in addition from the superior colliculus through the LP nucleus of the thalamus. Electrophysiological recordings have revealed that these visual inputs, which include cues about 3-dimensional target motion, are integrated in the LS cortex. The integrated output from LS cortex may provide the brainstem motor centers with the neural signals that facilitate eye movements, especially when the target is moving at high speeds. Outputs from the LS cortex travel directly to brainstem structures including the superior colliculus and pretectum. Evidence from monkey suggests that information may also travel to the mesencephalic reticular formation, where neurons have been recorded that are related to ocular convergence, lens accomodation or both. Although comparable data is lacking in the cat, it is suggested that the efferent circuit from the LS cortex to the motor nuclei in the brainstem included both the superior colliculus and the mesencephalic reticular formation. It is also suggested that this pathway is rather short, given that the mean latency of the early component of evoked disjunctive eye movements was approximately 60 ms.

Separation and identification of two native forms of spinach ferredoxin by hydrophobic chromatography.

Hydrophobic chromatography on a TSK-gel Phenyl-5PW column separated highly purified spinach ferredoxin into two distinct molecular species in their native forms. The two ferredoxins showed almost the same absorption spectra in spite of a difference in amino acid composition. Both ferredoxins were active in the NADPH-cytochrome c reducing system, and no significant difference was observed between their activities. The new separation method was also applied to ferredoxins highly purified from wheat plants and barley. Interestingly, all ferredoxin preparations so far examined contained two molecular species of ferredoxin.

Vapor-phase hydrazinolysis for microdetermination of carboxyl-terminal amino acids of proteins.

The "vapor-phase" hydrazinolysis method was devised for the microdetermination of the carboxyl-terminal residue of a protein. With this method, a polypeptide sample is degraded with vaporized hydrazine. The optimum conditions for hen egg-white lysozyme were established to be 2 to 4 h at 90 or 100 degrees C, the recovery of the carboxyl-terminal leucine being about 70%. With this vapor-phase method, side reactions are reduced and the time of hydrazinolysis is shortened. The limit of quantitation for the carboxyl-terminus of a protein is about 50 pmol, as judged so far with hen egg-white lysozyme. The carboxyl-termini of several proteins were determined using this novel procedure.

Purification and characterization of phospholipase A from Bungarus multicinctus venom.

Phospholipase A was purified 16.3-fold in terms of specific activity from the venom of Bungarus multicinctus by ion exchange chromatography on a CM-Sephadex C-25 column followed by gel filtration on a Sephadex G-75 column. The overall enzyme yield was 3.5% from the crude venom. The molecular weight and isoelectric point of the purified enzyme were estimated to be 14,000 and 7.9 by electrophoresis on SDS-polyacrylamide gel and on polyacrylamide gel for isoelectric focusing, respectively. The enzyme was a single polypeptide chain consisting of 118 amino acids. Its N- and C-terminal residues were asparagine and glutamine, respectively. The enzyme was stable in the pH range of 2--10 and retained full activity after incubation for 24 h at 37 degrees C. The optimum hydrolysis of egg yolk phosphatidyl choline was observed at pH 8.5 and the specific activity was 1,450 units per mg of the enzyme. The enzyme was inactivated by treatment with p-bromophenacyl bromide, accompanied by the loss of one of two histidine residues.

Amino acid sequence of phospholipase A from Bungarus multicinctus venom.

Bungarus multicinctus phospholipase A was reduced and carboxymethylated. The RCM-enzyme was digested with TPCK-trypsin or cleaved with cyanogen bromide followed by chymotrypsin digestion. The resulting peptide mixtures were fractionated by gel filtration on Sephadex G-50 and G-25 columns or by DEAE-cellulose (DE-32) column chromatography. Further purification of the peptide mixtures was performed by paper electrophoresis at pH 3.5 or 6.5 or by paper chromatography. The sequences of isolated peptides were determined by the manual Edman or dansyl-Edman method. From the sequences of these peptides the whole enzyme sequence (total 118 residues) was deduced. The complete sequence of the enzyme is similar to those of phospholipases A2 from other snake venoms and mammalian pancreas. Further, a 58% sequence homology was found between the present phospholipase A and the A chain of beta 1-bungarotoxin, a presynaptic neurotoxin having weak phospholipase A activity, contained in the same venom.