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C Schwabe

Publications and source records attributed to C Schwabe.

At least 91 records · Page 5Linked to original sources
PubMed1981

Isolation and characterization of relaxin from the sand tiger shark (Odontaspis taurus).

A peptide with relaxin activity in guinea pigs but not in mice has been extracted from the ovaries of pregnant sand tiger sharks (Odontaspis taurus). The structural similarity of this peptide to porcine relaxin includes molecular size approximately 6000 daltons), number of chains, and possibly, disulfide cross-links. The relaxin-type peptide isolated from shark ovaries contains the amino acid residues tyrosine, proline, and histidine, which are absent in the porcine hormone. The amino acid composition of shark relaxin, therefore, resembles that of porcine insulin to a greater extent than does the amino acid composition of porcine relaxin. This finding supports the idea that shark relaxin may be a primitive relaxin that has undergone fewer mutations than porcine relaxin since the putative duplication of the insulin gene. The data presented here suggest that the putative duplication of the insulin gene, which might have given rise to relaxin, has occurred much earlier than the separation of sharks from the general branch of animals that eventually gave rise to mammals.

Amino Acids↗
PubMed1980

Dipeptidyl peptidase II of bovine dental pulp. Initial demonstration and characterization as a fibroblastic, lysosomal peptidase of the serine class active on collagen-related peptides.

Dipeptidyl peptidase II (dipeptidylpeptide hydrolase, EC 3.4.14.2), previously known as dipeptidyl aminopeptidase II, was shown to be present in relatively high concentrations in bovine dental pulp. Based on the DNA content of tissue homogenates, the fibroblasts of this connective tissue appeared to contain more dipeptidyl peptidase II than the cells of lysosome-rich tissues such as bovine spleen and rat liver. The newly-recognized properties of dipeptidyl peptidase II, from both pulp and pituitary sources, included a marked propensity for hydrolyzing prolyl bonds at acidic pH. Lys-Pro-2-NNap and Lys-Pro-2(4-methoxy)naphthylamide (designed for cytochemical application) were hydrolyzed at rates equal to that of Lys-Ala-2-NNap. The impure pulp enzyme and the authentic pituitary enzyme showed comparable relative rates of hydrolysis on a variety of fluorogenic substrates with the general structure X-Pro-2-NNap (X = Lys, Arg, Phe, Ala or Gly), and on a variety of collagen-related tripeptides represented by X-Pro-Ala (X = Gly, Ala or Lys). The highest rates wee obtained on Lys-Ala-Ala and Lys-Ala-Pro. The pH optima for the hydrolysis of the 2-naphthylamide derivatives varied from 5.0 to 5.7, and for tripeptides from 4.2 to 5.3. In all cases the N-terminal dipeptide was released intact. Although previously unrecognized as a serine protease, dipeptidyl peptidase II (of pulp and pituitary origin) was strongly inhibited by (1 mM) diisopropyl phosphorofluoridate, p-nitrophenyl-p'-guanidinobenzoate, and phenylmethylsulfonyl fluoride. The enzyme, from both sources, was fully inhibited by 0.1 mM Lys-Ala chloromethyl ketone, a newly-designed, active-site-directed inhibitor. The numerous properties shared by the putative dipeptidyl peptidase II of bovine dental pulp and an authentic preparation of the bovine pituitary enzyme provided strong support for their having a common identity.

Animals↗
PubMed1979

A method for the estimation of esterase synthesis and degradation and its application to evaluate the influence of insulin and glucagon.

The irreversible reaction between liver esterases and the active-site-directed inhibitor bis(4-nitrophenyl)phosphate can be used in vivo both for the estimation of the esterase contents and for the measurement of the esterase degradation rates. A method based on this reaction is described which allows the simultaneous estimation of the rate constants of degradation and synthesis of esterases during a period of change in protein concentration. Rat liver was found to contain about 1 mg of organophosphate-binding esterases per g of fresh tissue while the microsomal fraction contains about 30 mg of esterases per g of microsomal protein. Esterase degradation and de novo synthesis were shown to remain in equilibrium for a period of at least five days following the injection of 10 mg bis(4-nitro-[14C]phenyl)phosphate per kg. The decrease of the relative amount of labeled esterases with time was found to follow first-order kinetics yielding an average esterase degrading constant of 0.0165 h-1 which corresponds to a half-life of 42 h. These data were confirmed by an independent experiment using one of the standard procedures for the estimation of degradation rates: [14C]leucine was incorporated and one of the esterases was subsequently isolated by immuno-precipitation. Using isoelectric focussing and dodecyl sulfate electrophoretic methods, the various esterase isoenzymes appeared to have very similar, if not identical turnover rates. This method for the estimation of the turnover characteristics was applied to evaluate hormone effects on liver esterases. The time course of the contents and the turnover of liver esterases was measured under the influence of glucagon treatment in diabetic rats and under the influence of high doses of insulin. The esterase content decreased faster than the average content of microsomal protein under the influence of glucagon. The reverse effect was observed with insulin-treated rats. Both insulin and glucagon apparently reduced the intracellular esterase turnover in rat liver. Kinetic analysis of the results revealed that insulin mainly lowered the esterase degradation rate, though the rate of esterase synthesis might also have been restricted. In the glucagon-treated rats the de novo synthesis of esterases was strongly reduced.

Animals↗
PubMed1978

Relaxin.

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Amino Acid Sequence↗
PubMed1978

Plasma immunoreactive relaxin levels in pregnant and nonpregnant women.

Immunoreactive relaxin was measured in plasma samples obtained from human volunteers utilizing the RIA procedure of Sherwood et al., as modified by O'Byrne and Steinetz for heterologous plasma samples. Immunoreactive hormone was not detected in samples obtained from men, and only rarely in plasma of nonpregnant women. Immunoreactive relaxin was present as early as the fourth week of pregnancy and was detectable throughout the course of gestation. Immunoreactive relaxin tended to be higher early in pregnancy, and there was no peak just before parturition as occurs in many other species. Our results are at variance with those of Bryant and coworkers, who reported high levels of immunoreactive relaxin in men and nonpregnant as well as pregnant women. The possible reasons for this discrepancy are presented.

Contraceptives, Oral, Combined↗
PubMed1978

[On connection between music therapy and music pedagogics during childhood (author's transl)].

In this article is explained, that, in spite of existing communities between music therapy and cooperating remedial education on the one hand and music education on the other, we can separate with regard to the method music therapy as one form of psychotherapy from educational influence. But in practice at therapy of children with psychical disturbances we always must take into considerations the education object in view.

Child↗
PubMed1977

Relaxin: a disulfide homolog of insulin.

Relaxin, a peptide hormone responsible for the widening of the birth canal in mammals, has been purified from the ovaries of pregnant hogs. The amino acid sequences of its constituent A and B chains were determined, and the positions of the disulfide cross-links were established. Relaxin was shown to be identical to insulin with respect to its disulfide bond distribution, but significant homology was lacking in other positions. These findings suggest that relaxin and insulin were derived from a common ancestral gene. Since the intrauterine mode of propagation is synonymous with the development of mammals, the genetic distance between insulin and relaxin should therefore permit an estimate of the earliest possible time of commitment of one evolutionary branch to the development of mammals. This event was estimated to have occurred about 5 X 10(8) years ago.

Amino Acid Sequence↗
PubMed1976

[Theroretical and methodological aspects of music therapy in children with special reference to international developmental tendencies].

Two melodiotherapeutical principles, namely, the isoprinciple and the intermediary principle (Benenzon), are described in the light of results of recent investigations into the communicative function of music (Reinecke). The paper also discusses the difference between methods of musicotherapy used in the treatment of mental disorders in children and adults. Finally, international trends are analyzed and conclusions drawn in respect of the development of a standard methodology of melodiotherapy.

Child↗