• Bulletin of the Korean Chemical Society
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• v.22 no.11
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• pp.1236-1242
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• 2001

(3S,1'S)-3-(1'-Carboxy-2'-phenyl)ethylamino-2-oxetanone (1a) and (3R,1'S)-3-(1'-carboxy-2'-phenyl)ethylamino-2-oxetanone (1b) were designed, synthesized, and evaluated as inhibitors for carboxypeptidase A, a prototypical zinc protease that removes the C-terminal amino acid having an aromatic side chain from oligopeptide substrate. It was concluded from the analysis of inhibition kinetics that while 1a inactivates CPA irreversibly, its diastereoisomer, 1b is a weak competitive inhibitor for CPA. A possible explanation for the observed difference in inhibition mode that is dependent on the inhibitor stereochemistry is offered.

• Bulletin of the Korean Chemical Society
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• v.23 no.4
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• pp.593-597
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• 2002

(R,S)- and (R)-2-Benzylcysteine (1) and (R,S)-2-phenethylcysteine (2) were synthesized and evaluated as inhibitors for carboxypeptidase A (CPA) with the expectation that these compounds exhibit improved inhibitory activities over 2-benzyl-3-mercaptopropanoic acid (BMPA), a potent CPA competitive inhibitor, possibly having additional interactions of their amino group with the carboxylate of Glu-270 of the enzyme upon binding to CPA. Contrary to the expectation, however, the CPA inhibitory potencies of these compounds were found to be much reduced compared with that of BMPA, suggesting that the amino group in the inhibitors rather exerts steric hindrance in binding of these inhibitors to CPA.

• Bulletin of the Korean Chemical Society
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• v.17 no.1
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• pp.34-38
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• 1996

2-(Azetidin-2-one-1-yl)-3-phenylpropionic acid and 2-(azetidin-2-thione-1-yl)-3-phenylpropionic acid were designed as potential active site directed inactivators for carboxypeptidase A, but shown to be they are competitive reversible inhibitors for the enzyme. The observation was somewhat surprising, but is not unexpected considering the recent report of Page who questioned the validity of the generally believed notion that $\beta-lactam$ ring is highly unstable.

• Bulletin of the Korean Chemical Society
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• v.18 no.10
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• pp.1100-1104
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• 1997

Compounds containing a nitrone moiety were designed, synthesized and evaluated as a new type of active site zinc ligating substrate analog inhibitors for carboxypeptidase A. The kinetic results indicated that they are competitive inhibitors for the enzyme, supporting the design rationale that the oxygen of the nitrone forms a coordinative bond to the active site zinc ion. The present study demonstrates that nitrone is useful as a zinc coordinating ligand in the design of inhibitors for zinc containing proteolytic enzymes.

• Archives of Pharmacal Research
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• v.29 no.3
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• pp.241-248
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• 2006

Angiotensin converting enzyme (ACE) inhibitors have cardioprotective effects in different species including human. This cardioprotective effect is mainly due to the inhibition of bradykinin (BK) degradation rather than inhibition of the conversion of angiotensin I to angiotensir. II. Bradykinin, a nonapeptide, has been considered to be the potential target for various enzymes including ACE, neutral endopeptidase 24.11, carboxypeptidase M, carboxypeptidase N, proline aminopeptidase, endopeptidase 24.15, and meprin. In the present study, the coronary vascular beds of Sprague Dawley rat isolated hearts were perfused (single passage) with Krebs solution alone or with different concentrations of BK i.e. $2.75{\times}10^{-10},\;10^{-7},\;10^{-6}\;and\;10^{-5}M$ solution. Percent degradation of BK was determined by radioimmunoassay. The degradation products of BK after passing through the isolated rat-hearts were determined using RP-HPLC and mass spectroscopy. All the four doses of BK significantly decreased the perfusion pressure during their passage through the hearts. The percentage degradation of all four doses was decreased as the concentration of drug was increased, implying saturation of a fixed number of active sites involved in BK degradation. Bradykinin during a single passage through the hearts degraded to give [1-7]-BK as the major metabolite, and [1-8]-BK as a minor metabolite, detected on HPLC. Mass spectroscopy not only confirmed the presence of these two metabolites but also detected traces of [1-5]-BK and arginine. These findings showed that primarily ACE is the major cardiac enzyme involved in the degradation of bradykinin during a single passage through the coronary vascular of bed the healthy rat heart, while carboxypeptidase M may have a minor role.

• Journal of the Korean Chemical Society
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• v.29 no.3
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• pp.295-303
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• 1985

Carboxypeptidase B from Salmo Salar eggs was purified by CM-cellulose, 0.5 ammonium sulfate saturation, DEAE-cellulose, and Sephadex G-75 gel filtration and its enzymatic properties were investigated. Optimum temperature was 55$^{\circ}C$, pH optima were 4.0 and 7.0 at 37$^{\circ}C$, and the enzyme was stable at pH 2.0∼3.0 and 5.5∼7.0 for 1.5h. This enzyme showed substrate specificity hydrolyzing the peptide bond of glycyl-L-arginine. Its K$_m$ values was 0.21mM, and the enzyme activity was stimulated by Cu$^{2+}$ and Fe$^{3+}$, while inhibited by Zn$^{2+}$. The lysine was found to be competitive inhibitor and its K$_i$ value was determined to be 4.3mM. Molecular weight of this enzyme was determined to be 36,400 daltons by SDS-PAGE and the enzyme was monomeric protein composed of 19 kinds of amino acid residues.

• Biomedical Science Letters
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• v.26 no.4
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• pp.256-266
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• 2020

Carboxypeptidase D (CPD) is a zinc-dependent protease, which is highly expressed in macrophages, and is thought to participate in inflammatory processes. In the present study, we investigated the possible regulatory effect of all-trans retinoic acid (ATRA), which is an active form of vitamin A and plays a critical regulatory role in both the innate and adaptive immunity, on CPD expression and secretion in human monocytic THP-1 cells. CPD mRNA expression first increased, from a concentration as low as 10 nM ATRA to a maximum level of expression, at 1 μM. ATRA enhanced intracellular CPD expression in a time- and concentration-dependent manner but did not affect cell surface CPD expression. Interestingly, 9-cis-RA did not affect CPD expression. Additionally, an experiment with RAR/RXR selective agonist or antagonists demonstrated that ATRA-induced enhancement of CPD expression was RAR/RXR dependent. ATRA also enhanced CPD secretion from THP-1 cells; however, this enhancement was RAR/RXR-independent. The anti-inflammatory agent dexamethasone reversed ATRA-induced enhancement of CPD expression and secretion. Our results suggest ATRA exerts regulatory effects on expression and secretion of CPD in human monocytes, and ATRA-induced CPD secretion may be associated with inflammatory response.

• Bulletin of the Korean Chemical Society
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• v.17 no.10
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• pp.967-969
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• 1996

• Bulletin of the Korean Chemical Society
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• v.15 no.9
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• pp.774-776
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• 1994

Ab initio studies of simple model systems for the carboxypeptidase A active site indicate that penta-and hexa-coordinate Zn(II) complexes have comparable structural stabilities. These facile coordination structures can be responsible for the catalytic role. Although the hexa-coordinate Zn(II) complex is more stable in enthalpy than the penta-coordinate Zn(II) complex, the entropy effect makes the latter as stable as or slightly more stable in free energy than the former.

• Bulletin of the Korean Chemical Society
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• v.19 no.2
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• pp.189-193
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• 1998

Carboxypeptidase-B (CPB) is involved in the biosynthesis of numerous peptide hormones and neurotransmitters. CPB catalyzes hydrolysis of the basic amino acids from the C-terminal position in polypeptides during posttranslational prohormonal processing. Various peptides containing thiaarginine residue at C-terminal position were synthesized and tested for their hydrolysis by CPB. A colorimetric assay, employing Ellman's reagent to detect the thioguanidine released upon hydrolysis of the dipeptide substrates, showed that thiaarginine is a suitable mimetic for arginine. Kinetic studies on the four substrates, Z-L-Ala-DL-thia-Lys, Z-L-Ala-DL-thia-Arg, Z-L-Lys-DL-thia-Arg, and Z-L-Lys(Boc)-DL-thia-Arg, gave Km (mM) of 0.66, 5.08, 0.024, and 0.006 and kcat (min-1) of 340, 5200, 151 and 335, respectively.