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Biomedical subjects

H Holzer

Publications and source records attributed to H Holzer.

At least 145 records · Page 8Linked to original sources
PubMed1979

Primary structure of yeast proteinase B inhibitor 2.

The complete amino acid sequence of yeast proteinase B inhibitor 2 (IB2) was determined to be H3N+-Thr-Lys-Asn-Phe-Ile-Val-Thr-Leu-Lys-Lys-Asn-Thr-Pro-Asp-Val-Glu-Ala-Lys-Lys-Phe-Leu-Asp-Ser-Val-His-His-Ala-Gly-Gly-Ser-Ile-Leu-His-Glu-Phe-Asp-Ile-Ile-Lys-Gly-Tyr-Thr-Ile-Lys-Val-Pro-Asp-Val-Leu-His-Leu-Asn-Lys-Leu-Lys-Glu-Lys-His-Asn-Asp-Val-Ile-Glu-Asn-Val-Glu-Asp-Lys-Glu-Val-His-Thr-Asn-COO-. Elucidation of the primary structure was enabled by automated Edman degradation and COOH-terminal hydrolysis with carboxypeptidases A (bovine pancreas and Y (yeast). IB2 is the first proteinase inhibitor to be sequenced that possesses a structure devoid of disulfide bridges.

Amino Acid Sequence↗
PubMed1979

[Continuous determination of the blood density during haemodialysis (author's transl)].

Application of the mechanical oscillator technique for measurement of blood density, in combination with a reference method for the determination of the absolute value of the blood volume, enables precise and continuous monitoring of fluid shifts during haemodialysis. The significant correlation between blood volume and density or plasma volume and density allows each variation in blood volume to be calculated from the blood density and the slope of the regression line for each individual patient. The possibility of taking continuous measurements and the high accuracy of the mechanical oscillator technique commends this method for the measurement of short-term and small fluid shifts.

Blood Pressure↗
PubMed1979

[Application of the mechanical oscillator technique for the measurement of blood density and hematocrit (author's transl)].

Density measurements were performed with an accuracy of 0.01 g/l by means of a density meter based on the "mechanical oscillator technique", on human whole blood, on plasma, and on erythrocyte concentrates. A highly significant correlation between blood density and hematocrit was found. If plasma and red cell densities are known, hematocrit can be estimated more precisely than using the centrifugation method. This fact is important if small variations of the hematocrit are to be determined. Such variations can be produced, e.g., by alteration of the transcapillary filtration equilibrium. Furthermore, the statistical distribution of plasma and erythrocyte densities allows to determine the range of variation of blood densities for certain hematocrit values and vice versa.

Blood↗
PubMed1979

Purification and molecular characterization of two inhibitors of yeast proteinase B.

A rapid purification procedure for large scale preparations of yeast proteinase B inhibitors 1 and 2 (IB1 and IB2) is described. By disc gel electrophoresis, amino acid analysis, and end-group determinations, each of the inhibitors is homogeneous. Both inhibitors are polypeptides with molecular weights of 8,500, containing 74 residues. No components other than amino acids could be detected. There is no significant difference in the amino acid compositions of the two inhibitors as analyzed after acid hydrolysis. Both polypeptides are characterized by the total absence of arginine, tryptophan, and sulfur-containing amino acid residues. The proteinase B inhibitors of yeast, therefore, differ fundamentally from proteinase inhibitors of many other organisms, which generally contain a large number of disulfide bridges. Both proteinase B inhibitors have threonine as the NH2-terminal residue and -Val-His-Thr-Asn-COO- as the COOH-terminal sequence. Comparison of peptide maps after tryptic digestion reveals that the two inhibitors differ definitely in only a few tryptic peptides. The inhibitors are rapidly inactivated by digestion with carboxypeptidase A from bovine pancreas at pH 8.5. Inactivation occurs stoichiometrically with the release of threonine, the penultimate residue at the COOH-terminal end of both inhibitors.

Amino Acids↗
PubMed1979

Chemical and physical properties of the carboxypeptidase Y-inhibitor from Baker's yeast.

The purification as well as some characteristics of the carboxypeptidase Y-inhibitor from baker's yeast have been described in a previous report (Matern, H., Hoffmann, M. and Holzer, H. (1974) Proc. Natl. Acad. Sci. U.S. 71, 4874-4878). In this paper, chemical and physical properties of the purified inhibitor are presented. The molecular weight was estimated at 23 400--24 000 and appears to be a monomeric unit. Amino acid analysis and carbohydrate studies are given, showing the existence of three disulfide bonds and one sulfhydryl group per molecule and the absence of carbohydrate residues. The N-terminal amino acid is blocked by an acetyl group. The C-terminal amino acid is lysine. The isoelectric point (pI) is 6.6 and the inhibitor-enzyme complex is stable (at 25 degrees C) betwen pH 5 and 9. The apparent Ki value was calculated as 2.5.10(-9)M.

Amino Acids↗
PubMed1979

Rapid decrease of ATP content in intact cells of Saccharomyces cerevisiae after incubation with low concentrations of sulfite.

Sulfite, at concentrations above 1 mM and at a pH below 4, caused cell death in Saccharomyces cerevisiae X2180 as measured by the colony-forming capacity. A rapid decrease in the ATP content was observed prior to cellular death. The depletion of ATP was reversible and the lethal effect could be prevented if the cells were exposed to sulfite for periods of less than 1 h. Extent and rate of ATP depletion were dependent on time, pH value, temperature and sulfite concentrations.

Adenosine Triphosphate↗
PubMed1979

Isolation, characterization and localization of the proteinase B inhibitor IB3 from Saccharomyces carlsbergensis.

A heat-stable polypeptide has been detected in Saccharomyces carlsbergensis which inhibits specifically proteinase B from yeast. This proteinase B inhibitor IB3 differs substantially in chemical, physical and antigenic properties from the earlier described proteinase B inhibitors IB1 and IB2 from yeast. The inhibitor IB3 has been purified from S. carlsbergensis and appears to be homogeneous by disc gel electrophoresis and sodium dodecyl sulfate gel electrophoresis. The molecular weight has been estimated at 11 500, with no evidence for the existence of subunits. The amino acid analysis shows the absence of tryptophan. No compounds other than amino acids could be detected. The isoelectric point is 4.6. The inhibitor is not affected by incubation with proteinase B but is inactivated by proteinase A and carboxypeptidase Y from yeast and by trypsin from bovine pancreas. The proteinase B inhibitor association constant was calculated to be 3.3 x 10(9) M-1 and the enzyme inhibitor complex is stable at 25 degrees C in the pH range 5--10. The inhibitor does not exhibit immunological cross-reactivity with IB1 and IB2. After centrifugal fractionation at 40 000 x g of a metabolic lysate from spheroplasts the inhibitor was found to be localized in the supernatant, i.e. the extravacuolar soluble fraction.

Amino Acids↗
PubMed1979

[The calculation of hemoglobin concentration from blood and plasma densities, measured by the mechanical oscillator technique (author's transl)].

Blood samples from patients were taken for the measurement of blood and plasma densities by the mechanical oscillator technique, and the hematocrit value and the hemoglobin content of the blood. The values for blood and plasma density permit the precise calculation of blood hemoglobin concentration and hematocrit. Thus, in addition to the calculation of total protein concentration of plasma (Holzer et al (1978) J. Clin. Chem, Clin. Biochem. 16, 391--395), measurement of the blood density yields two further relevant parameters. In total, only 3 ml of blood are needed for the measurements.

Hematocrit↗
PubMed1979

[The effect of aldosterone antagonists in juvenile heart surgery].

In children with congenital heart disease duration and extent of hyperaldosteronism and the influence of spironolactone after surgery with a heart-lung-machine, were evaluated by direct measurement of plasma aldosterone levels. Secondary hyperaldosteronism as seen in 11 patients without spironolactone-therapy after surgery did not persist very long. 14 children receiving spironolactone immediately after surgery showed an onset of drug efficacy at a period when plasma aldosterone in the group without spironolactone had begun to fall. As a practical consequence, spironolactone treatment should be initiated a few days prior to surgery in order to achieve full efficacy on the day of surgery.

Adolescent↗
PubMed1978

Studies on the carboxypeptidase Y-inhibitor complex of yeast.

We report in vitro studies on the interaction of several substrates with the carboxypeptidase Y-inhibitor complex of yeast. Inhibition of carboxypeptidase Y cleavage of two peptides by carboxypeptidase Y-inhibitor is shown to be competitive. The experiments show a wide variation in the degree of cleavage of a variety of peptide substrates by carboxypeptidase Y, despite the presence of the inhibitor protein. The most likely explanation for this behaviour is a different capacity for the peptides to dissociate the inhibitor protein from the substrate-binding site of carboxypeptidase Y. While the carboxypeptidase Y-inhibitor is insensitive to proteolytic inactivation when complexed with carboxypeptidase Y, it is sensitive when in the free state. Addition of the substrate, N-Cbz-Phe-Leu, to the carboxypeptidase Y-inhibitor complex, however, allows proteolytic inactivation of the inhibitor protein. We suggest that the proteinase-inhibitor may play a crucial role in the regulation of proteinase activity. The inhibitor protein generally protects proteins from unwanted proteinase action. However, it will allow cleavage of proteins which, by some signal triggered metabolically, become substrates due to the exposure of amino acid sequences normally buried, and exhibiting a high affinity for the proteinase.

Carboxypeptidases↗
PubMed1978

Azotaemia in severe head injury--central dysregulation or renal failure?

We have investigated serum urea, uric acid, and creatinin crealinine levels in 39 patients with craniocerebral trauma. The most impressive observation was a change in serum urea, which was found significantly increased up to 237 mg% on the seventh day (mean value) after severe injury, and turned out to be of great prognostic value. Patients with a serum urea above 100 mg% did not survive the acute stage. Uric acid and creatinine were only significantly increased in patients with lethal outcomes, the first being elevated by about 300% in the first week, the second remaining normal for four days increasing thereafter. It is concluded from these first data that a hypercatabolic state due to shock, central dysregulation, or both, is responsible for the dissociated behaviour of urea, uric acid and creatinine during the first four days, after which renal failure as a secondary change is shown by the rise in serum creatinine.

Brain↗
PubMed1978

Molecular weight and hydrodynamic properties of a proteinase A inhibitor from baker's yeast.

The molecular weight of the proteinase A inhibitor IA3 from baker's yeast was determined by different methods. From gel-filtration experiments, a molecular weight of 19 000 was calculated for the native inhibitor, while under denaturing conditions a molecular weight of 7400 was found. From electrophoretic experiments with the native protein, a molecular weight of 9000 was calculated. A similar value was obtained from the analytical ultracentrifuge, even at a protein concentration of 12 mg/ml. The diffusion coefficient and the partial specific volume were measured and from these data the frictional ratio and the Stokes radius were calculated. These parameters indicate that the relatively high apparent molecular weight calculated from the gel-filtration experiments is caused by the assymetric shape of the inhibitor molecule rather than by an aggregation of subunits.

Chemical Phenomena↗
PubMed1978

A new inhibitor protein from rat uterus against yeast proteinase B.

An inhibitor of yeast proteinase B has been enriched from uterine smooth muscle (myometrium) of the rat. This inhibitor behaves like a glycoprotein and has a molecular weight of 90 000. It activity can be clearly distinguished from the proteinase inhibitory activity of serum. Proteinase B inhibitory activity has also been demonstrated in liver, lung, heart, skeletal muscle, spleen and brain and these activities, too, are clearly distinguishable from the serum inhibitory activity. The activity in rat uterus decreases during the postpartal period.

Animals↗
PubMed1978

[Determination of the serum protein concentration based on the measurement of density by the mechanical oscillator technique (author's transl)].

A linear relation is well established between the density and protein concentration of the serum. The measurement of protein concentration by a new technique for the determination of the absolute density, the mechanical oscillator technique, was investigated. The method is based on the determination of the resonant frequency of a mechanical bending-type, U-shaped glass tube oscillator filled with the sample. The shift in the resonant frequency of the oscillator caused by the mass of the defined volume of the sample taking part in the vibration can be used to calculate the density or protein concentration of the sample. In spite of the low specificity of the method, the interference of substances like glucose, urea or triglycerides is small. Simplicity and rapid results of high accuracy recommend the mechanical oscillator technique for the routine laboratory.

Blood Glucose↗
PubMed1978

[Hypophyseal dysfunction and chronic hemodialysis].

65 chronic hemodialysed patients showed a mean elevation of serum prolactin up to 35.5 ng/ml and a mean HGH level of 4.2 ng/ml, whereas TSH was within normal range. The response of the prolactin secretion to TRH was poor in patients with a high basal prolactin level. Patients with amenorrhea showed significantly higher prolactin values than menstruating women. It is assumed, that chronic stress caused the elevation of prolactin and HGH.

Adolescent↗