13433-04-0Relevant academic research and scientific papers
Transport and Metabolic Pathway of Thymocartin (TP4) in Excised Bovine Nasal Mucosa
Lang, Steffen,Langguth, Peter,Oschmann, Rainer,Traving, Birgit,Merkle, Hans P.
, p. 1190 - 1196 (1996)
Thymocartin (TP4, Arg-Lys-Asp-Val) is the 32-35 fragment of the naturally occuring thymic factor (thymopoietin). Here studies on the nasal transport and metabolism of TP4 were performed. Freshly excised bovine nasal mucosa was taken as a model membrane. For permeation studies typical donor-receiver experiments (side-by-side) and finite-dose experiments with small volumes of highly concentrated solutions were carried out. The metabolic pathway of TP4 in nasal mucosa was found to occur according to a typical amino-peptidase cleavage pattern, stepwise forming Lys-Asp-Val and Asp-Val. TP4 metabolism experiments under reflection kinetics showed a saturation profile above 0.5 μmol mL-1. A non-linear kinetic model consisting of three steps in sequence was sufficient to describe the kinetics: for the first step saturable Michaelis-Meat kinetics, and for the second and the third step first-order kinetics were assured. The model was capable of simultaneously fitting the data for the full range of initial concentrations from 0.1 up to 1.0 μmol mL-1. Saturation kinetics was also found to be the prominent feature of the permeation experiments performed. In the lower concentration range (-1), transport of TP4 across nasal mucosa was controlled by metabolism, in the higher concentration range (>0.85 μmol mL-1) diffusion control became more important. We conclude that enhancement of absorption can be achieved when nasal ammopeptidases are saturated, e.g. at high TP4 concentrations.
Peptide inhibitors of leukocyte adhesion
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, (2008/06/13)
The present invention provides novel peptides derived from portions of the sequence of amino acids 42-48 of P-selectin. The invention also provides pharmaceutical compositions comprising the peptides of the invention, and diagnostic and therapeutic methods utilizing the peptides and pharmaceutical compositions of the invention.
Isolation and identification of urinary β-aspartyl dipeptides and their concentrations in human urine
Tanaka,Nakajima
, p. 617 - 625 (2007/10/05)
β-Aspartyl-methionine, -aspartic acid and -glutamic acid and γ-glutamyl-threonine and -glycine were isolated and identified in human urine by means of ion-exchange chromatography, highvoltage paper electrophoresis, acid hydrolysis and determination of N-terminal amino acids of the isolated compounds, and comparison of their behaviors in paper electrophoresis and chromatography with those of the authentic compounds. The concentrations of acidic β-aspartyl dipeptides in human urine were determined using an amino acid analyzer. Their concentrations were as follows: β-aspartyl-glycine, male, 44.4±8.5, female, 61.4±18.9, child, 83.7±27.1; -alanine, male, 11.0±4.9, female, 20.7±12.0, child, 25.3±9.1; -glutamic acid, male, 10.0±3.7, female, 23.0±8.5, child, 20.4±7.5; -serine, male, 9.9±2.8, female, 13.6±3.8, child, 14.9±4.7; -aspartic acid, male, 4.3±1.0, female, 9.1±2.2, child, 18.4±6.5; -threonine, male, 3.9±0.9, female, 5.8±1.1, child, 13.2±4.9 μmol/g creatinine (mean ± S.D.). The order of the sum of their concentrations tended to be child>female>male. Patients receiving intravenous hyperalimentation also excreted acidic β-aspartyl dipeptides into urine in amounts similar to those in females and in a pattern similar to that observed in healthy persons. This finding indicates that urinary β-aspartyl dipeptides were probably of endogenous origin because oral nutrition was stringently excluded in these patients.
