Kazuko OHGI

Role of Histidine 46 in the Hydrolysis and the Reverse Transphosphorylation Reaction of RNase Rh from Rhizopus niveus (1997)

Irie, Masachika, Ohgi, Kazuko, Iwama, Masanori, Koizumi, Machiko, Sasayama, Etsuko, Harada, Kishiko, ...

In order to study the reaction mechanism of RNase Rh from Rhizopus niveus, the rates of cleavage of four 2′3′-cyclic nucleotides by mutant enzymes of RNase Rh, H46F, H109F, E105Q, and K108L were...

Enzymatic Properties of Mutant Forms of RNase Rh from Rhizopus niveus as to Asp51 (1996)

Ohgi, Kazuko, Takeuchi, Mitsuaki, Iwama, Masanori, Irie, Masachika

In order to determine the role of Asp51 of RNase Rh from Rhizopus nimus, enzymes with mutations at the 51st position, D51N,D51E,D51Q, D51S,D51T,D51A,and D51K, were prepared, and their enzymatic...

Enzymatic Properties of Mutant Enzymes at Trp49 and Tyr57 of RNase Rh from Rhizopus niveus (1996)

Ohgi, Kazuko, Takeuchi, Mitsuaki, Iwama, Masanori, Irie, Masachika

In order to establish the role of Tyr57 and Trp49 in the enzymatic reaction of RNase Rh, several mutant enzymes at Tyr57 and Trp49 were prepared by protein engineering and their enzymatic properties...

Role of Lys108 in the Enzymatic Activity of RNase Rh from Rhizopus niveus (1995)

Ohgi, Kazuko, Iwama, Masanori, Tada, Kuriko, Takizawa, Ritsue, Irie, Masachika

In order to elucidate on the mechanism of action of RNase Rh from Rhizopus niveus, we investigated the role of Lys108, which is conserved among the RNase T2 family RNases except for two cases. The...

Purification and Primary Structure of a New Guanylic Acid Specific Ribonuclease from Pleurotus ostreatus (1994)

Nomura, Hideyuki, Inokuchi, Norio, Kobayashi, Hiroko, Koyama, Takashi, Iwama, Masanori, Ohgi, Kazuko, ...

A guanine nucleotide-specific RNase (RNase Po1) was isolated from caps of the fruit bodies of Pleurotus ostreatus. RNase Po1 is most active towards RNA at pH 8.0. The effect of heating on the molar...

pH Profile of Kinetic Constants of RNase Rh from Rhizopus niveus and Its Mutant Enzymes towards UpU, and Possible Mechanisms of RNase Rh (1994)

Irie, Masachika, Ohgi, Kazuko, Watanabe, Hideaki, Iwama, Masanori, Nakamura, Kazuo T., Kurihara, Hiroyuki, ...

In order to elucidate the mechanism of action of Rhizopus niveus RNase Rh, we investigated the pH profiles of the kinetic parameters of RNase RNAP Rh, a derivative of RNase Rh, and its mutant...

Characterization of Poly C Preferential Ribonuclease from Chicken Liver (1993)

Hayano, Kumi, Iwama, Masanori, Sakamoto, Hiroko, Watanabe, Hideaki, Sanda, Akihiro, Ohgi, Kazuko, ...

Poly C preferential RNase previously reported by Levy and Karpetsky [J. Biol. Chem. 255, 2153–2159 (1980)] and Miura et al. [Chem Pharnu Bull 32, 4053–4060 (1984)] was extensively purified from...

Role of Asp51 and GlulO5 in the Enzymatic Activity of a Ribonuclease from Rhizopus niveus (1993)

Ohgi, Kazuko, Horiuchi, Hiroyuki, Watanabe, Hideaki, Iwama, Masanori, Takagi, Masamichi, Irie, Masachika

The active site of a base non-specific RNase from Rhizopus niveus (RNase Rh), consists of three histidine residues and one carboxyl group [Ohgi, K. et al. (1992) J. Biochem. 111, 132–138]. In order...

Purification, Some Properties, and Primary Structure of a Base Non-Specific Ribonuclease from Oyster (Crussdstrea grigus) (1993)

Watanabe, Hideaki, Narumi, Hiroaki, Inaba, Tomio, Ohgi, Kazuko, Irie, Masachika

A ribonuclease (RNase Oy) was purified to homogeneity on SDS-PAGE from the homogenate of oyster (Crussdstrea grigus). The apparent molecular weight estimated from SDS-PAGE was ca. 28 kDa. The pH...

Evidence That Three Histidine Residues of a Base Non-Specific and Adenylic Acid Preferential Ribonuclease from Rhizopus niveus Are Involved in the Catalytic Function (1992)

Ohgi, Kazuko, Horiuchi, Hiroyuki, Watanabe, Hideaki, Iwama, Masanori, Takagi, Masamichi, Irie, Masachika

In order to study the structure-function relationship of an RNase T2 family enzyme, RNase Rh, from Rhizopus niveus, we investigated the roles of three histidine residues by means of site-specific...

Expression of RNase Rh from Rhizopus niveus in Yeast and Characterization of the Secreted Proteins (1991)

Ohgi, Kazuko, Horiuchi, Hiroyuki, Watanabe, Hideaki, Takagi, Masamichi, Yano, Keiji, Irie, Masachika

The full-length cDNA encoding RNase Rh, which is secreted extracellularly by Rhizopus niveus, was isolated and its nucleotide sequence was determined. It was placed under control of the promoter of...

Comparative Base Specificity, Stability, and Lectin Activity of Two Lectins from Eggs of Rana catesbeiana and R. japonica and Liver Ribonuclease from R. catesbeiana (1991)

Okabe, Yukie, Katayama, Naoko, Iwama, Masanori, Watanabe, Hideaki, Ohgi, Kazuko, Irie, Masachika, ...

Two lectins with RNase activity obtained from eggs of Rana catesbeiana and R. japonica and RNase obtained from R. catesbeiana liver show 65–83% protein homology. The base specificity of these frog...

Isolation, Characterization, and Primary Structure of a Base Non-Specific and Adenylic Acid Preferential Ribonuclease with Higher Specific Activity from Trickoderma viride (1991)

Inada, Yoichi, Watanabe, Hideaki, Ohgi, Kazuko, Irie, Masachika

In order to elucidate the structure-function relationship of RNases belonging to the RNase T2 family (base non-specific and adenylic acid-preferential RNase), an RNase of this family was purified...

Primary Structure of an Alkaline Ribonuclease from Bovine Liver (1990)

Hosoya, Kenji, Nagareda, Yasuo, Hasemi, Shuichi, Sanda, Akihiro, Takizawa, Yoshio, Watanabe, Hideaki, ...

A pyrimidine base specific and most basic alkaline RNase named RNase BL4 was isolated from bovine liver as a protein showing a single band on slab gel-electrophoresis. The enzyme is most active at pH...

Primary Structure of a Base Non-Specific and Adenylic Acid Preferential Ribonuclease from Aspergillus saitoi (1990)

Watanabe, Hideaki, Naitoh, Akiko, Suyama, Yuka, Inokuchi, Norio, Shimada, Hiroko, Koyama, Takashi, ...

The complete primary structure of a base non-specific and adenylic acid preferential RNase (RNase M) from Aspergillus saitoi was determined. The sequence was determined by analysis of the peptides...

The Difference Spectra of Bovine Kidney RNase K2 Induced upon Binding with Nucleotides Markedly Differ from Those of Bovine Pancreatic RNase (1989)

Irie, Masachika, Ohgi, Kazuko, Nitta, Reiko, Ikeda, Miyuki, Ueno, Motoko

The difference spectra obtained upon the addition of nucleotides to bovine kidney RNase, which shows 40% sequence homology with bovine pancreatic RNase, are markedly different from those of bovine...

Primary Structure of a Ribonuclease from Bullfrog (Rana catesbeiana) Liver (1989)

Nitta, Reiko, Katayama, Naoko, Okabe, Yukie, Iwama, Masanori, Watanabe, Hideaki, Abe, Yasuko, ...

A pyrimidine base-specific ribonuclease was purified from bullfrog (Rana catesbeiana) liver by means of CM-cellulose column chromatography and affinity chromatography on heparin-Sepharose CL-6B,...

Primary Structure of a Base Non-Specific Ribonuclease from Rhizopus niveus (1988)

Horiuchi, Hiroyuki, Yanai, Koji, Takagi, Masamichi, Yano, Keiji, Wakabayashi, Eiji, Sanda, Akihiro, ...

The primary structure of a base non-specific ribonuclease from Rhizopus niveus (RNase Rh) was determined by nucleotide sequence analysis of the DNA fragment encoding RNase Rh gene including signal...

Primary Structure of a Ribonuclease from Bovine Brain (1988)

Watanabe, Hideaki, Katoh, Hideo, Ishii, Masami, Komoda, Yuko, Sanda, Akihiro, Takizawa, Yoshio, ...

The primary structure of a pyrimidine base-specific ribonuclease from bovine brain was determined. The sequence determined is...

Purification of Acid Ribonucleases from Bovine Spleen (1988)

Ohgi, Kazuko, Sand, Akihiro, Takizawa, Yoshio, Jrie, Masachika

Two acid RNases were purified from bovine spleen by means of ammonium sulfate fractionation, chromatographies on. phospho-cellulose, heparin-Sepharose CL-6B, poly G-Sepharose, and 2',...

Primary Structure of a Non-Secretory Ribonuclease from Bovine Kidney (1988)

Irie, Masachika, Nitta, Reiko, Ohgi, Kazuko, Niwata, Yasushi, Watanabe, Hideaki, Iwama, Masanori, ...

The primary structure of a non-secretory ribonuclease from bovine kidney (RNase K2 was determined. The sequence determined was...

Site of Alkylation of the Major Ribonuclease from Aspergillus saitoi with Iodoacetate (1986)

IRIE, Masachika, WATANABE, Hideaki, OHGI, Kazuko, HARADA, Masatomi

A base non-specific and adenylic acid preferential ribonuclease from Aspergillus saitoi (RNase M) was modified by [14C]iodoacetic acid. RNase M was inactivated with concomitant incorporation of about...

Distribution of Two Urinary Ribonuclease-Like Enzymes in Human Organs and Body Fluids (1986)

MORITA, Toru, NIWATA, Yasushi, OHGI, Kazuko, OGAWA, Michio, IRIE, Masachika

In order to determine the distribution of two human urinary RNase (RNase Us and RNase UL)-like enzymes in human tissues and body fluids, enzyme immunoassay systems were established using rabbit...

Roles of Lysine1 and Lysine7 Residues of Bovine Pancreatic Ribonuclease in the Enzymatic Activity (1986)

IRIE, Masachika, OHGI, Kazuko, YOSHINAGA, Makiko, YANAGIDA, Tamami, OKADA, Yoshio, TENO, Naoki

1) In order to investigate the roles of Lys1 and Lys7 of RNase A in the enzymatic activity, four S-peptide derivatives were prepared and their abilities to activate S-protein were measured. They are...

The Subsite Structures of Guanine-Specific Ribonucleases and a Guanine-Preferential Ribonuclease. Cleavage of Oligoinosinic Acids and Poly I (1985)

WATANABE, Hideaki, ANDO, Eiichi, OHGI, Kazuko, IRIE, Masachika

In order to estimate the size of the active site of guanylic acid specific R Nases (R Nase T1 from Aspergillus oryzae and R Nase St from Streptomyces erythreus) and guanine preferential R Nase (R...

Purification and Properties of Bovine Kidney Ribonucleases (1985)

NIWATA, Yasushi, OHGI, Kazuko, SANDA, Akihiro, TAKIZAWA, Yoshio, IRIE, Masachika

Two RNases (RNases K1 and K2) were purified from bovine kidney by means of column chromatography on phospho-cellulose, Sephadex G-50, CM-cellulose, heparin-Sepharose, and Agarose-APUP. They were...

Kinetic Studies on the Cleavage of Oligouridylic Acids and Poly U by Bovine Pancreatic Ribonuclease A (1984)

IRIE, Masachika, MIKAMI, Fumiko, MONMA, Kumiko, OHGI, Kazuko, WATANABE, Hideaki, YAMAGUCHI, Ryoji, ...

Kinetic parameters, Km and Vmax for the transesterification of oligouridylic acid, (Up)nU> p (n = 0–4), by RNase A were measured spectrophotometrically at pH 7.0 and 25°C. The kinetic...

Some Evidence Suggesting the Existence of P2 and B3 Sites in the Active Site of Bovine Pancreatic Ribonuclease A (1984)

IRIE, Masachika, WATANABE, Hideaki, OHGI, Kazuko, TOBE, Mayumi, MATSUMURA, Go, ARATA, Yoji, ...

In order to clarify the subsite structure of ribonuclease A (RNase A), the interactions of pdTp, pAp, dTpdAp, and pdTpdAp with RNase A were investigated by means of kinetic studies and 31P NMR...

Characterization of Two Forms of Base Non-Specific and Adenylic Acid Preferential Ribonuclease from Aspergillus saitoi (1983)

OHGI, Kazuko, WATANABE, Hideaki, TAKIZAWA, Mayumi, KIMURA, Yoshie, MATSUTANI, Koichi, KAKINUMA, Etsuko, ...

Two forms of RNases (RNase MLL and RNase MM) from Aspergillus saitoi which are base non-specific and adenylic acid preferential were separated from each other by DEAE-cellulose column chromatography....

Studies on Salivary Gland Ribonucleases. III. Purification and Properties of Three Ribonucleases from Bovine Parotid Gland (1983)

KUMAGAI, Hiroshi, YOSHIHARA, Keiko, UMEMOTO, Mitsue, IGARASHI, Kazuei, HIROSE, Seiyu, OHGI, Kazuko, ...

Three alkaline ribonucleases [EC 3.1.4.221 were purified 4,500- to 7,850-fold from bovine parotid gland by repeated CM-Sephadex C-25 chromatography and Sephadex G-50 gel filtration, with a total...

Primary Structure of a Minor Ribonuclease from Aspergillus saitoi (1982)

WATANABE, Hideaki, OHGI, Kazuko, IRIE, Masachika

1. RNase Ms, a base non-specific RNase from Aspergillus saitoi was reduced and carboxymethylated (RCM-RNase Ms). RCM-RNase Ms was hydrolyzed with tryp-sin, and the trypsin digests were then treated...

Alkylation of a Ribonuclease from Streptomyces erythreus with Iodoacetate and Iodoacetamide (1981)

OHGI, Kazuko, WATANABE, Hideaki, EMMAN, Kiyoshi, YOSHIDA, Nobuo, IRIE, Masachika

1. RNase St was inactivated by iodoacetate. The inactivation was most rapid at pH 5.0-7.0. Competitive inhibitors protected RNase St from inactivation by iodoacetate. The protective effect of...

Purification and Properties of Human Urine Ribonuclueases (1981)

IWAMA, Masanori, KUNIHIRO, Motoko, OHGI, Kazuko, IRIE, Masachika

1. Two RNases (RNase UL and RNase US) were purified from the urine of human adults by means of column chromatographies on SP-Sephadex C-50, phospho-cel-lulose and CM-cellulose and gel-filtration on...

Further Evidence for the Existence of the p0 Site in the Active Site of Ribonuclease. The Binding of Thymidine 3', 5'-Diphosphate to Ribonuclease (1981)

IWAHASHI, Kazuyuki, NAKAMURA, Kazuo (Torii), MITSUI, Yukio, OHGI, Kazuko, IRIE, Masachika

Binding of thymidine 3′,5′-diphosphate to ribonuclease was studied by spectroscopic, kinetic and crystallographic methods. The results show that the 5′-phosphate group is located close to the...

Carboxamidomethylation of a Ribonuclease from Aspergillus saitoi (1980)

OHGI, Kazuko, IRIE, Masachika

The inactivation of a RNase from Aspergillus saitoi (RNase Ms) was studied to obtain information on its active site. Inactivation of RNase Ms by iodoacetamide was greater at an alkaline pH, and was...

Carboxymethylation of a Minor Ribonuclease from Aspergillus saitoi (1979)

OHGI, Kazuko, IRIE, Masachika

RNase Ms was inactivated by iodoacetate. The inactivation was most rapid at pH 6.0, and was inhibited in the presence of a denaturant such as 8 M urea or 6 M guanidine-HCl. Competitive inhibitors...

Modification of an Arginine Residue of a Base-Nonspecific Ribonuclease from Aspergillus saitoi (1979)

WATANABE, Hideaki, OHGI, Kazuko, IRIE, Masachika

1. A base-nonspecific ribonuclease from Aspergillus saitoi [RNase Ms, EC 3.1.4.23; molecular weight, 12,500] was modified with phenyiglyoxal (PG) and I ,2-cyclohexanedione (CHD) in order to...

pH-Profiles of the Kinetic Parameters of a Minor Ribonuclease from Aspergillus saitoi (1978)

IRIE, Masachika, OHGI, Kazuko

In order to investigate the nature of amino acid residues involved in the active site of a ribonuclease from Aspergillus saitoi, the pH-profiles of kinetic parameters of RNase Ms were measured. (1)...

Circular Dichroism Studies on the N-Bromosuccinimide Oxidation of Ribonuclease from Aspergillus saitoi (1977)

OHGI, Kazuko, IRIE, Masachika

The NBS oxidation of RNase M, which is base non-specific, was studied mainly by circular dichroism spectroscopy. It was found that tryptophan residues of RNase M were resistant to NBS at pH's from...

Photooxidation and Carbethoxylation of a Minor Ribonuclease from Aspergillus saitoi (1977)

IRIE, Masachika, OHGI, Kazuko, IWAMA, Masanori

In order to investigate the nature of amino acid residues involved in the active site of a ribonuclease from Aspergillus saitoi, the pH dependence of the rates of inactivation of RNase Ms by...

The Effect of Modification of Amino-Groups of the Minor Ribonuclease from Aspergillus saitoi on the Enzymatic Activity (1977)

OHGI, Kazuko, KIRYU, Michiko, TORANO, Yumiyo, HORI, Yasuko, WATANABE, Hideaki, IWAMA, Masanori, ...

In order to investigate whether amino-groups are involved directly in the active site of RNase Ms, a minor ribonuclease from Asp. saitoi, trinitrophenylation of RNase Ms was investigated. At pH 7.7...

Further Studies on the Specificity of the Minor Ribonuclease from Aspergillus saitoi (1976)

IRIE, Masachika, OHGI, Kazuko

In order to investigate the base specificity of the minor RNase [EC 3.1. 4. 23] from Aspergillus saitoi, the kinetic constant of the enzyme was measured with 16 dinucleoside phosphates (XpY's) as...

Purification and Properties of a New Ribonuclease from Aspergillus saitoi (1975)

OHGI, Kazuko, IRIE, Masachika

From a commercial digestive produced from Aspergillus saitoi, a ribonuclease [EC 3.1.4.23] having a molecular weight of 12,500 has been isolated in addition to the RNase reported previously, which...