-
[show abstract]
[hide abstract]
ABSTRACT: Neurofibromas are benign tumors that comprise primarily of Schwann cells and fibroblasts. Mast cells have been found scattered in the tumor tissue, and their role in promoting the proliferation of neurofibroma has been suggested. Tranilast (N-[3,4-dimethoxycinnamolyl]anthranilic acid) is an anti-allergic drug that inhibits release of the chemical mediators from mast cells and it used for the treatment of keloids and hypertrophic scars by its inhibition of growth-promoting transforming growth factor (TGF)-beta(1) from fibroblasts. We assumed that tranilast would suppress neurofibroma cell growth. In order to prove this hypothesis, we investigated the effectiveness of tranilast in inhibiting the tumor growth using a new cell culture system obtained from patients with neurofibromas. We called this culture system with the mixture of Schwann cells and fibroblasts "NF1 cells culture". Mast cells were differentiated from CD34(+) peripheral blood mononuclear cells of normal healthy subjects, and were co-cultured with NF1 cells. Three days after tranilast (10 approximately 100 microM) added to the culture dishes, we counted viable cell numbers and measured the concentrations of TGF-beta(1), stem cell factor (SCF) and tryptase, which exists in the histamine granule, in the culture medium. Tranilast significantly suppressed proliferation of the NF1 cells and lowered the levels of TGF-beta(1), SCF and tryptase. These results suggest that tranilast retards tumor proliferation through not only suppression of cell growth factor, but also the inhibition of a chemical mediator released from mast cells. Thus, tranilast can be a potent therapeutic agent to inhibit the growth of neurofibromas.
The Tohoku Journal of Experimental Medicine 04/2009; 217(3):193-201. · 1.24 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In this study, we present a propeptide-like cysteine proteinase inhibitor, Drosophila CTLA-2-like protein (D/CTLA-2), a CG10460 (crammer) gene product, with an amino acid sequence significantly similar to the proregion of Drosophila cysteine proteinase 1 (CP1). Recombinant D/CTLA-2, expressed in E. coli, strongly inhibited Bombyx cysteine proteinase (BCP) with a Ki value of 4.7 nM. It also inhibited cathepsins L and H with Ki values of 3.9 (human liver) and 0.43 (rabbit liver) nM, and 7.8 nM (human liver), respectively. Recombinant D/CTLA-2 exhibited low but significant inhibitory activities to cathepsin B with Ki values of 15 nM (human liver) and 110 nM (rat liver), but hardly inhibited papain. We attempted to purify cysteine proteinases inhibited by D/CTLA-2 from total bodies of adult Drosophila. Recombinant D/CTLA-2 significantly inhibited CP1 with a Ki value of 12 nM, indicating that CP1, a cognate enzyme of D/CTLA-2, is a target enzyme of the inhibitor in Drosophila cells. These results indicate that D/CTLA-2 is a selective inhibitor of cathepsin L-like cysteine proteinases similar to other propeptide-like cysteine proteinase inhibitors such as Bombyx cysteine proteinase inhibitors (BCPI) and cytotoxic T-lymphocyte antigen-2 (CTLA-2). D/CTLA-2 was expressed over the whole life cycle of Drosophila. Strong expression was observed in the garland cells and prothoracic gland in the late stages of embryonic development. These results suggest that D/CTLA-2, implicated in intra- and extra-cellular digestive processes, functions in these tissues by suppressing uncontrolled enzymatic activities of CP1.
ZOOLOGICAL SCIENCE 02/2007; 24(1):21-30. · 0.95 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Fumarase (EC 4.2.1.2) from Corynebacterium glutamicum (Brevibacterium flavum) ATCC 14067 was purified to homogeneity. Its amino-terminal sequence (residues 1 to 30) corresponded to the sequence (residues 6 to 35) of the deduced product of the fumarase gene of C. glutamicum (GenBank accession no. BAB98403). The molecular mass of the native enzyme was 200 kDa. The protein was a homotetramer, with a 50-kDa subunit molecular mass. The homotetrameric and stable properties indicated that the enzyme belongs to a family of Class II fumarase. Equilibrium constants (K(eq)) for the enzyme reaction were determined at pH 6.0, 7.0, and 8.0, resulting in K(eq)=6.4, 6.1, and 4.6 respectively in phosphate buffer and in 16, 19, and 17 in non-phosphate buffers. Among the amino acids and nucleotides tested, ATP inhibited the enzyme competitively, or in mixed-type, depending on the buffer. Substrate analogs, meso-tartrate, D-tartrate, and pyromellitate, inhibited the enzyme competitively, and D-malate in mixed-type.
Bioscience Biotechnology and Biochemistry 06/2006; 70(5):1102-9. · 1.28 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We have determined the cDNA sequence encoding bovine mitochondrial ATP-dependent Lon protease. Since the 5'-end region of the cDNA was highly GC-rich and thus could not be amplified by the 5'-RACE method, a genomic DNA fragment containing an in-frame ATG was isolated and sequenced. The translated amino acid sequence contained 961 amino acids with a calculated molecular weight 106,665. Sequence similarities of the bovine enzyme to human and E. coli orthologs were 92 and 27%, respectively. The N-terminal amino acid sequence seemed to be a mitochondrial targeting signal. To determine the cleavage site of the signal sequence we analyzed the mature enzyme purified from bovine adrenocortical mitochondria. Analysis of CNBr-digested peptides revealed that the N-terminus was heterogeneous. We suggest that nonspecific aminopeptidase might remove several amino acids from the N-terminus after mitochondrial processing peptidase has cleaved Gly(67)-Leu(68) or Leu(68)-Trp(69).
DNA Sequence 01/2006; 16(6):474-8. · 0.75 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In the field of dermatology and plastic and reconstructive surgery, fibrin gel is regarded as a material that promotes wound healing. To test the hypothesis that fibrin may promote the growth of the epidermis, we examined its effects on the proliferation of cultured keratinocytes. Human keratinocytes were cultivated in fibrin-coated wells, and the cell numbers and transforming growth factor (TGF)-alpha, secreted into the cultured medium, were measured. We also assessed the capacity of epidermal growth factor receptor (EGF-R) that is responsible for all known actions of TGF-alpha and epidermal growth factor. The keratinocytes increased dramatically in their number, and the TGF-alpha secretion and the binding capacity of EGF-R were also increased dramatically in the presence of fibrin. These findings suggest that fibrin supports the proliferation of keratinocytes in an autocrine fashion via EGF-R; namely, fibrin stimulates keratinocytes to secrete TGF-alpha, which in turn increases cell proliferation and EGF-R capacity. We propose that fibrin can support the wound healing process of the epidermis via the TGF-alpha/EGF-R pathway.
The Tohoku Journal of Experimental Medicine 10/2005; 207(1):33-40. · 1.24 Impact Factor
-
Yoshiyuki Matsumoto,
Ken-Ichi Morishima,
Akira Honda, Shoji Watabe,
Misa Yamamoto,
Masayuki Hara,
Masaki Hasui,
Chikako Saito,
Toshimitsu Takayanagi,
Tsutomu Yamanaka,
Nakamichi Saito,
Hideaki Kudo,
Nobuhiko Okamoto,
Masato Tsukahara,
Shinya Matsuura
[show abstract]
[hide abstract]
ABSTRACT: Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive malformation syndrome characterized by microcephaly, syndactyly of toes, ambiguous genitalia, and mental retardation. The underlying DHCR7 gene has been identified and a wide variety of distinct mutations were reported in USA and European SLOS patients. A significant difference has been suggested in the frequency of SLOS among different ethnic populations. Here, we report mutational analysis of seven Japanese SLOS patients. Five mutations, R352Q, R242H, G303R, X476Q, and S192F, were identified, and R352Q appeared most frequent, since nine out of the 13 mutations of Japanese origin were the same R352Q. These results suggest that R352Q is a predominant founder mutation in Japanese SLOS patients.
Journal of Human Genetics 02/2005; 50(7):353-6. · 2.57 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Cytotoxic T-lymphocyte antigen-2 (CTLA-2) is a novel cysteine proteinase inhibitor. The protein sequence is homologous to the proregion of mouse cathepsin L. Here, we report the expression, purification, and characterization of recombinant CTLA-2 (CTLA-2alpha). CTLA-2alpha was cloned into the pET16b vector and the plasmid was transformed into Escherichia coli strain BL21 (DE3) pLysS. The recombinant CTLA-2alpha was highly expressed and purified by His-Bind affinity chromatography, Factor Xa digestion, and hydrophobic chromatography. Throughout these procedures, 3mg recombinant CTLA-2alpha was obtained from 450 ml of bacterial culture medium. The purified protein exhibited inhibitory activities towards certain cysteine proteinases and was properly refolded, as indicated by circular dichroism spectroscopy. Recombinant CTLA-2alpha fully inhibited Bombyx cysteine proteinase (BCP) (overall Kd (Ki*) = 0.23 nM) and and cathepsin L (overall Kd (Ki*) = 0.38 nM). Inhibition of cathepsin H ( Ki = 86 nM) and papain ( Ki = 560 nM) was much weaker, while inhibition of cathepsin B was negligible ( Ki > 1 microM). Our results indicate that mouse CTLA-2alpha is a selective inhibitor of the cathepsin L-like cysteine proteinases.
Protein Expression and Purification 11/2003; 32(1):119-25. · 1.59 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Mitochondrial thioredoxin reductase was purified from bovine adrenal cortex. The enzyme is a first protein component in the mitochondrial thioredoxin-dependent peroxide reductase system. The purified reductase exhibited an apparent molecular mass of 56 kDa on SDS/PAGE, whereas the native protein was about 100 kDa, suggesting a homodimeric structure. It catalysed NADPH-dependent reduction of 5,5′dithiobis(2-nitrobenzoic acid) and thioredoxins from various origins but not glutathione, oxidized dithiothreitol, dl-α-lipoic acid, or insulin. Amino acid and nucleotide sequence analyses revealed that it had a presequence composed of 21 amino acids which had features characteristic of a mitochondrial targeting signal. The amino acid sequence of the mature protein was similar to that of bovine cytosolic thioredoxin reductase (57%) and of human glutathione reductase (34%) and less similar to that of Escherichia coli (19%) or yeast (17%) enzymes. Human and bovine cytosolic thioredoxin reductase were recently identified to contain selenocysteine (Sec) as one of their amino acid constituents. We also identified Sec in the C-terminal region of mitochondrial (mt)-thioredoxin reductase by means of MS and amino acid sequence analyses of the C-terminal fragment. The four-amino acid motif, Gly-Cys-Sec-Gly, which is conserved among all Sec-containing thioredoxin reductases, probably functions as the third redox centre of the enzyme, as the mitochondrial reductase was inhibited by 1-chloro-2,4-dinitrobenzene, which was reported to modify Sec and Cys covalently. It is known that mammalian thioredoxin reductase is different from bacterial or yeast enzyme in, for example, their subunit molecular masses and domain structures. These two different types of enzymes with similar activity are suggested to have evolved convergently. Our data clearly show that mitochondria, which might have originated from symbiotic prokaryotes, contain thioredoxin reductase similar to the cytosolic enzyme and different from the bacterial one.
European Journal of Biochemistry. 12/2001; 264(1):74 - 84.
-
[show abstract]
[hide abstract]
ABSTRACT: In the crude extract of mature eggs of the pernyi silkworm moth, Antheraea pernyi, proteolytic activity was detected in the acidic pH region, with maximal activity at pH 3.5., however, no appreciable activity was observed in the neutral to alkaline pH region. The enzyme activity was strongly inhibited by cysteine proteinase inhibitors, such as iodoacetic acid (IAA) and N-[N-(L-3-trans-carboxyoxirane-2-carbony)-l-leucyl] agmatine (E-64); whereas, pepstatin, diisopropyl fluorophosphate (iPr2P-F), and EDTA were without effect, suggesting the enzyme to be a cysteine proteinase. From the substrate specificity, major proteinase in the eggs is likely to be a cathepsin B-like proteinase. When the crude extract of eggs was incubated at pH 4.0, enzymatic activity appeared after a few minutes lag period, indicating that the enzyme was stored in a latent form in the eggs and thus was activated during the incubation. Pepstatin completely inhibited the activation but had no effect on the activated enzyme, suggesting that aspartic protease (s) was involved in this activation. The proteinase was found in vitro to readily degrade yolk polypeptides, as well as hemoglobin and other substrates. In the pupal ovary, this activity gradually increased during embryogenesis, reaching a maximum at days 10 after pupal ecdysis. After reaching a maximum, the level of cysteine proteinase remained approximately constant and the high activity was maintained during embryogenesis. The results altogether suggest that an acid cysteine proteinase (ACP) is stored as a latent form in the eggs and is implicated in yolk protein degradation of Antheraea pernyi eggs during embryogenesis.
Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology.
-
[show abstract]
[hide abstract]
ABSTRACT: Bombyx cysteine proteinase inhibitor (BCPI) is a novel cysteine proteinase inhibitor. The protein sequence is homologous to the proregions of certain cysteine proteinases. Here we report the mechanism of its inhibition of several cysteine proteinases. BCPI strongly inhibited Bombyx cysteine proteinase (BCP) activity with aK i = 5.9 pM, and human cathepsin L with a K i = 36 pM. The inhibition obeyed slow-binding kinetics. The inhibition of cathepsin H was much weaker (K i = 82 nM), while inhibition of papain CK i 4µM) and cathepsin B (J£i≫ 4 nM) was negligible. Following incubation with BCP, BCPI was first truncated at the C-terminal end, and then gradually degraded over time. The truncation mainly involved two C-terminal amino acid residues. Recombinant BCPI lacking the two C-terminal amino acid residues still retained substantial inhibitory activity. Our results indicate that BCPI is a stable and highly selective inhibitor of cathepsin L-like cysteine proteinases
