Enzymatic degradation studies of endomorphin-2 and its analogs containing N-methylated amino acids

The design of peptide-based therapeutics is generally based on the replacement of l-amino acids with d-isomers to obtain improved therapeutic efficiency.

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Enzymatic degradation studies of pectin and cellulose from red beets

Nahrung/Food ◽

10.1002/1521-3803(20011001)45:5<324::aid-food324>3.0.co;2-c ◽

2001 ◽

Vol 45 (5) ◽

pp. 324 ◽

Cited By ~ 8

Author(s):

G. Dongowski

Keyword(s):

Enzymatic Degradation ◽

Degradation Studies

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THE PROPERTIES AND THE ENZYMATIC DEGRADATION OF DESOXYRIBONUCLEOPROTEIN FROM LIVER CELL NUCLEI

The Journal of General Physiology ◽

10.1085/jgp.41.3.595 ◽

1958 ◽

Vol 41 (3) ◽

pp. 595-608 ◽

Cited By ~ 32

Author(s):

Kenneth J. Monty ◽

Alexander L. Dounce

Keyword(s):

Amino Acids ◽

Cell Nucleus ◽

Liver Cell ◽

Enzymatic Degradation ◽

Short Peptides ◽

Chromosomal Protein ◽

X Rays ◽

Cell Nuclei ◽

Desoxyribonucleic Acid ◽

Mode Of Attachment

The isolation and properties of a desoxyribonucleoprotein of the rat liver cell nucleus are described. This material consists of DNA (desoxyribonucleic acid) bound to the residual chromosomal protein by what appear to be covalent linkages. Lipide is present, but can be removed by extraction in lipide solvents prior to isolation of the nucleoprotein, without much change in the physical properties of the latter. The nucleoprotein in question forms elastic, recoilable gels in molar saline at pH 7.0 or in water at pH 8.0 to 10.0 or even higher, which are similar to those that can be obtained from whole nuclei. The effects of x-rays, heat, and enzymes on the nucleoprotein are discussed, and the composition of the protein component is investigated. The latter contains an "occult" protein that can be liberated by heating in 0.1 N HCl. A study of the enzymatic degradation of the desoxyribonucleoprotein has been made, with the aim of attempting the isolation of small polynucleotide fragments attached to amino acids or short peptides that might be useful in characterizing the mode of attachment of the desoxyribonucleic acid to the protein in the desoxyribonucleoprotein. Evidence is presented indicating that such products can be isolated through the use of electrophoresis on paper.

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The Enzymatic Degradation of Angiotensin II Analogues by proteolytic enzyme in vitro

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y72-017 ◽

1972 ◽

Vol 50 (2) ◽

pp. 113-118 ◽

Cited By ~ 2

Author(s):

M. C. Carrara ◽

D. Regoli ◽

W. K. Park

Keyword(s):

Amino Acids ◽

Angiotensin Ii ◽

Unnatural Amino Acids ◽

Enzymatic Degradation ◽

Leucine Aminopeptidase ◽

Receptor Interaction ◽

Angiotensin I ◽

Peptide Receptor ◽

Angiotensin Ii Analogues

Angiotensin II (ATII), angiotensin I (ATI), and Acpc analogues of ATII, 8-Achc-ATII, 8-D-Phe-ATII, and 8-Ala-ATII, were incubated in vitro with carboxypeptidase, chymotrypsin, and leucine-aminopeptidase in order to study the influence of unnatural amino acids (Acpc, Achc, and D-Phe) and of L-Ala on the activity of peptidases.Fragments occurring during the breakdown of peptides were demonstrated by paper chromatography in an ascending system.ATII and ATI are rapidly inactivated by carboxypeptidase and chymotrypsin, while the degradation by leucine-aminopeptidase is slower.Substitution of L-Phe with Acpc, Achc, D-Phe, or L-Ala in position 8 prevents the degradation by carboxypeptidase. Chymotrypsin degrades 3-Acpc-ATII and 5-Acpc-ATII but not 4-Acpc-ATII. The action of leucine-aminopeptidase is not influenced by substituting Acpc to each one of the first five amino acids composing the molecule of angiotensin.The possible implications of these findings for the peptide-receptor interaction is discussed.

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