Serine carboxypeptidases

The crystal structure of the HNL isolated from S. bicolor (SbHNL) was determined in a complex with the inhibitor benzoic acid." The folding pattern of SbHNL is similar to that of wheat serine carboxypeptidase (CP-WII)" and alcohol dehydrogenase." A unique two-amino acid deletion in SbHNL, however, is forcing the putative active site residues away from the hydrolase binding site toward a small hydrophobic cleft, thereby defining a completely different active site architecture where the triad of a carboxypeptidase is missing. 

SHIRLEY, A.M., McMICHAEL, C.M., CHAPPLE, C The sng2 mutant of Arabidopsis is defective in the gene encoding the serine carboxypeptidase-like protein sinapoylglucose Choline sinapoyltransferase, Plant J., 2001, 28, 83-94. 

U. H. Mortensen, S. J. Remington, K. Breddam, Site-Directed Mutagenesis on (Serine) Carboxypeptidase Y. A Hydrogen Bond Network Stabilizes the Transition State by Interaction with the C-Terminal Carboxylate Group of the Substrate , Biochemistry 1994, 33, 508-513. 

Milkowski, C. and Strack, D., Serine carboxypeptidase-like acyltransferases. Phytochemistry, 65, 517, 2004. 

Pfizenmaier, Molecular cloning of hydroxynitrile lyase from Sorghum hicolor (L.). Homologies to serine carboxypeptidases. Plant Mol. Biol. 1994, 26, 735 -746. 

T. L. Bullock, K. Breddam, S. J. Remington, Peptide aldehyde complexes with wheat serine carboxypeptidase II, implications for the catalytic mechanism and substrate specificity. /. Mol. Biol. 1996, 255, 714-725. 

Many secreted proteins, as well as smaller peptide hormones, are acted upon in the endoplasmic reticulum by tryptases and other serine proteases. They often cut between pairs of basic residues such as KK, KR, or RR.214-216 A substilisin-like protease cleaves adjacent to methionine.217 Other classes of proteases (e.g., zinc-dependent carboxypeptidases) also participate in this processing. Serine carboxypeptidases are involved in processing human prohormones.218 Among the serine carboxypeptidases of known structure is one from wheat219 and carboxypeptidase Y, a vacuolar enzyme from yeast.220 Like the pancreatic metallocarboxypeptidases discussed in Section 4, these enzymes remove one amino acid at a time, a property that has made carboxypeptidases valuable reagents for determination of amino acid sequences. Carboxypeptidases may also be used for modification of proteins by removal of one or a few amino acids from the ends. 

Lehfeldt, C., Shirley, A. M., Meyer, K., Ruegger, M. O., Cusumano, J. C., Viitanen, P. V., Stack, D., and Chappie, C., 2000, Cloning of the SNG1 gene of Arabidopsis reveals a role for a serine carboxypeptidase-1 ike protein as an acyltransferase in secondary metabolism, Plant Cell 12 1295-1306. 

Comparison of the deduced sequence of A. saitoi carboxypeptidase with other known serine carboxypeptidase sequences shows that they share a low degree of similarity 32% with wheat carboxypeptidase II, 32.3% with malt carboxypeptidase II and 26.2% with yeast carboxypeptidase Y (Figure 19) [88], However, all of the sequences conserve the catalytic domains (indicated by boxes II to IV in Figure 19) and the domain (box I in the Figure 19) which contains the amino acid residues recognizing the C-terminal carboxylate group of peptide substrates. There are also present in the sequence ten potential sites for N-linked glycosylation. 

Figure 19. Comparison of the peptide domains reportedly required for enzyme catalysis in eukaryotic serine carboxypeptidases.

Takeuchi, M., and Ichishima, E. (1989). Action of serine carboxypeptidases from Aspergillus saitoi on carboxyterminal amidated peptides. Agric. Biol. Chem., 53, 2301-2306. 

Blinkovsky, A. M., Byun, T., Brown, K. M., and Gohghtly, E. J. 1999. Purification, characterization, and heterologous expression in Fusarium venenatum of a novel serine carboxypeptidase from Aspergillus oryzae. Appl. Env. Microbiol., 65, 3298-3303. 

Baumert, A., Milkowski, C., Schmidt, J., Nimtz, M., Wray, V. and Strack, D. (2005) Formation of a complex pattern of sinapate esters in Brassica napus seeds, catalyzed by enzymes of a serine carboxypeptidase-like acyltransferase family Phytochemistry, 66,1334- 5. 

Fraser, C.M., Thompson, M.G., Shirley, A.M., Ralph, J., Schoenherr, J.A., Sinlapadech, T., Hall, M.C. and Chappie, C. (2007) Related Arabidopsis serine carboxypeptidase-like sinapoylglucose acyltransferases display distinct but overlapping substrate specificities. Plant Physiol, 144, 1986-99. 

Shirley, A.M. and Chappie, C. (2003) Biochemical characterization of sinapoylglu-cose choline sinapoyltransferase, a serine carboxypeptidase-Uke protein that functions as an acyltransferase in plant secondary metabolism.. Biol. Chem., 278, 19870-7. 

Stehle, R, Brandt, W., Milkowski, C. and Strack, D. (2006/2007) Structure determinants and substrate recognition of serine carboxypeptidase-like acyltransferases from plant secondary metabolism. FEES Lett., 580, 6366-74 and 581, 164-5. 

Du/tripeptidyl-peptidases Peptidyl-dipeptidases Serine carboxypeptidases MetaUocarboxypeptidases Cysteine carboxypeptidases Omega peptidases Serine endopeptidases Cysteine endopeptidases Aspartic endopeptidases MetaUoendopeptidases Threonine endopeptidases Other endopeptidases... 

The following proteins were chosen for multiple sequence alignment T. califomica acetylcholinesterase, Xanthobacter autotrophicus haloalkane dehalogenase, G. candidum lipase and wheat serine carboxypeptidase. This set was selected because they are all members of the o/fi hydrolase fold family (Ollis et al, 1992). This family of proteins, which is believed to have evolved by... 

It is well established that the same three-dimensional scaffolding in proteins often carries constellations of amino acids with diverse enzymatic functions. A classic example is the large family of a/jS, or TIM, barrel enzymes (Farber and Petsko, 1990 Lesk et ai, 1989). It appears that lipases are no exception to date five other hydrolases with similar overall tertiary folds have been identified. They are AChE from Torpedo calif arnica (Sussman et al., 1991) dienelactone hydrolase, a thiol hydrolase, from Pseudomonas sp. B13 (Pathak and Ollis, 1990 Pathak et al, 1991) haloalkane dehalogenase, with a hitherto unknown catalytic mechanism, from Xanthobacter autotrophicus (Franken et al, 1991) wheat serine carboxypeptidase II (Liao et al, 1992) and a cutinase from Fusa-rium solani (Martinez et al, 1992). Table I gives some selected physical and crystallographic data for these proteins. They all share a similar overall topology, described by Ollis et al (1992) as the a/jS hydrolase... 

First, the structure of wheat serine carboxypeptidase II described by Liao et al. (1992) serves as good evidence of possible relationships. Serine carboxypeptidases are found in virtually every higher organism (Breddam, 1986), and some are of considerable importance, such as the proteinase involved in the regulation of blood pressure in humans (Odya and Erdos, 1981). 

Liao, D.L, Breddam, K., Sweet, R. M., Bullock, T. and Remington, S.). (1992) Refined atomic model of wheat serine Carboxypeptidase-I I at 2.2-Angstrom resolution. Biochemistry 31, 9796-9812... 

Molecular and enzymatic properties of serine carboxypeptidase (EC.3.4.1.6.1, CPase Top), isolated and refined from the common squid (Todarodes pacificus) liver, were studied. It was found that this enzyme reacts well at the C-terminal position of peptides having hydrophobic amino acids. Because of this property, it was anticipated that this enzyme would have the effect of eliminating bitterness of some peptides. This enzyme was used on bitter peptides prepared by hydrolysis of proteins with pepsin and trypsin. It was found that this CPase Top can eliminate bitter peptides prepared from soy protein and com gluten. 

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