Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.55 (PTR)
 433 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

N-arginine dibasic convertase (NRD convertase) (accession number L27124) is a metalloendopeptidase from rat brain cortex and testis which cleaves peptide substrates on the N-terminus of arginine residues in basic doublets. Its predicted amino acid sequence contains the putative zinc binding motif HXXEH in a region which exhibits 35% and 48% similarity with E coli protease III (pitrilysin E.C 3.4.99.44) and rat or human insulinase (E.C 3.4.99.45) respectively. This feature clearly classifies this endopeptidase as a member of the pitrilysin family of zinc-metalloproteases. However, the NRD convertase sequence contains a distinctive additional feature consisting of a 71 acidic amino acid stretch. Its substrate selectivity and the characteristic motifs of its amino acid sequence allow us to propose this new metalloendopeptidase as the first member of a new class of processing enzymes.
 ...
PMID:N-arginine dibasic convertase (NRD convertase): a newcomer to the family of processing endopeptidases. An overview. 781 28

N-Arg dibasic convertase is a metalloendopeptidase from rat brain cortex and testis that cleaves peptide substrates on the N terminus of Arg residues in dibasic stretches. By using both an oligonucleotide and antibodies to screen a rat testis cDNA library, a full-length cDNA was isolated. The sequence contains an open reading frame of 1161 codons corresponding to a protein of 133 kDa that exhibits 35% and 48% similarity with Escherichia coli protease III (pitrilysin, EC 3.4.99.44) and rat or human insulinase (EC 3.4.99.45), respectively. Moreover, the presence of the HXXEH amino acid signature (XX = FL) clearly classifies N-Arg dibasic convertase as a member of the pitrilysin family of zinc-metalloendopeptidases. In addition, a Cys residue that may be responsible for the thiol sensitivity of the insulinase and N-Arg dibasic convertase was proposed. The protein sequence contains a distinctive additional feature consisting of a stretch of 71 acidic amino acids. We hypothesize that this metalloendopeptidase may be a member of a distinct class of processing enzymes.
 ...
PMID:N-arginine dibasic convertase, a metalloendopeptidase as a prototype of a class of processing enzymes. 801 18

An endoprotease and an aminopeptidase B were isolated from rat testis and characterized. The first one is a metalloendopeptidase of 1161 residues which contains a canonical HXXEHX76E Zn(2+)-binding site and an acidic stretch of 71 amino acids containing 79% of Glu and Asp. It exhibits an in vitro selectivity for peptide bonds at the N-terminus of Arg (R) moieties in dibasic sites and was thus called NRD convertase (Nardilysin: EC 3.4.24.61). It belongs to the pitrilysin family and shows 24 and 34% identity with E. coli protease III (EC 3.4.24.54) and insulysin (EC 3.4.24.55) respectively. The aminopeptidase B component is a 72 kDa metalloexopeptidase which is able to remove Lys and Arg residues from naphtylamide derivatives and from the N-terminus of various peptide substrates. A combination of biochemical and immunochemical studies revealed its ubiquitous character. In the testis, both enzymes are highly expressed at late stages of spermatogenesis and NRD convertase expression is exclusively restricted to the germ cells. The subcellular localization of both enzymes supports the involvement of aminopeptidase B in processing events associated with the secretory pathway but led to new hypothesis on the possible physiological role(s) of NRD convertase.
 ...
PMID:NRD convertase and aminopeptidase B: two processing metallopeptidases with a selectivity for basic residues. 968 93

Glyoxysomes are a subclass of peroxisomes involved in lipid mobilization. Two distinct peroxisomal targeting signals (PTSs), the C-terminal PTS1 and the N-terminal PTS2, are defined. Processing of the PTS2 on protein import is conserved in higher eukaryotes. The cleavage site typically contains a Cys at P1 or P2. We purified the glyoxysomal processing protease (GPP) from the fat-storing cotyledons of watermelon (Citrullus vulgaris) by column chromatography, preparative native isoelectric focusing, and 2D PAGE. The GPP appears in two forms, a 72-kDa monomer and a 144-kDa dimer, which are in equilibrium with one another. The equilibrium is shifted on Ca(2+) removal toward the monomer and on Ca(2+) addition toward the dimer. The monomer is a general degrading protease and is activated by denatured proteins. The dimer constitutes the processing protease because the substrate specificity proven for the monomer (Phi-Arg/Lys downward arrow) is different from the processing substrate specificity (Cys-Xxx downward arrow/Xxx-Cys downward arrow) found with the mixture of monomer and dimer. The Arabidopsis genome analysis disclosed three proteases predicted to be in peroxisomes, a Deg-protease, a pitrilysin-like metallopeptidase, and a Lon-protease. Specific antibodies against the peroxisomal Deg-protease from Arabidopsis (Deg15) identify the watermelon GPP as a Deg15. A knockout mutation in the DEG15 gene of Arabidopsis (At1g28320) prevents processing of the glyoxysomal malate dehydrogenase precursor to the mature form. Thus, the GPP/Deg15 belongs to a group of trypsin-like serine proteases with Escherichia coli DegP as a prototype. Nevertheless, the GPP/Deg15 possesses specific characteristics and is therefore a new subgroup within the Deg proteases.
 ...
PMID:Dual specificities of the glyoxysomal/peroxisomal processing protease Deg15 in higher plants. 1759 11