Purification and characterization of a human urine ribonuclease (RNAase 1) showing genetic polymorphism

Production and characterization of murine monoclonal anti-human DNase II antibodies, and their use for immunoaffinity purification of DNase II from human liver and urine

Four murine monoclonal anti-human deoxyribonuclease II (DNase II) antibodies were obtained from BALB/c mice immunized with human DNase II purified from human liver. Both single radial enzyme diffusion (SRED) and DNA-cast polyacrylamide gel electrophoresis (DNA-cast PAGE) were very useful for obtaining the DNase II-specific antibodies. All of the antibodies showed specific inhibition of human DNase II enzyme activity and specific immunostaining of the 32-kDa enzyme band, which is one of the three non-identical subunits of human DNase II molecule separated by sodium dodecyl sulfate (SDS)-PAGE followed by blotting on a transfer membrane. A formyl-cellulofine resin conjugated with each antibody specifically adsorbed and efficiently desorbed the active DNase II enzyme. Insertion of the immunoaffinity step in our purification procedure made the purification of human DNase II easier, faster and more effective than the conventional procedure.

Purification and characterization of a novel poly(U), poly(C) ribonuclease from Saccharomyces cerevisiae

A new ribonuclease from Saccharomyces cerevisiae, specific for poly(U) and poly(C) substrate, was purified near to homogeneity by successive fractionation with DEAE-Sepharose, Heparin-Sepharose and CM-Sepharose chromatography. The purified molecule detected by SDS/polyacrylimide gel electrophoresis has a molecular mass of 29 kDa. The optimum pH for the enzyme activity is 5.5-7 and its isoelectric point is 7.5. The purified enzyme was able to degrade 26S, 18S and 5S rRNAs as well as mRNA obtained from in vitro transcription. No catalytic activity was observed when the RNase was incubated with tRNA and double stranded substrate. Our findings suggest that this novel RNase may play an important role in the processing of RNA in Saccharomyces cerevisiae.

Rabbit DNase I: purification from urine, immunological and proteochemical characterization, nucleotide sequence, expression in tissues, relationships with other mammalian DNases I and phylogenetic analysis

DNase I from rabbit urine was purified approx. 3600-fold to apparent homogeneity with a 41% yield by affinity chromatography utilizing DNA-cellulose; the purity of the final preparation was assessed by SDS/PAGE, lack of contamination by other nucleases and production of a monospecific antibody against the enzyme. Although the proteochemical and enzymological properties of the purified enzyme resembled those of other mammalian DNases I, the enzymic activity of rabbit DNase I was less efficiently inhibited by monomeric actin than was that of human DNase I, probably due to substitution of an amino acid residue involved in actin binding (Tyr-65 to Phe). The effects of specific antibodies to human, rabbit and rat DNases I on the activities of the corresponding purified enzymes revealed that human DNase I lies between the rat and rabbit enzymes with regard to its immunological properties. An 1158 bp full-length cDNA encoding rabbit DNase I was constructed from the total RNA of rabbit pancreas using a combination of reverse transcriptase-PCR and rapid amplification of cDNA ends, followed by sequencing. This identified a 17- or 21-amino-acid signal sequence, with the mature enzyme containing 260 amino acids and a single N-glycosylation site at Asn-18. The amino acid sequence deduced from the cDNA sequence exactly matched that determined proteochemically from the purified enzyme up to residue 20. A systematic survey of DNase I distribution as measured by both enzymic activity and DNase I gene transcripts in 12 rabbit tissues showed the pancreas and parotid gland to produce equivalent levels, higher than those in other tissues. Enzymic activity and DNase I gene expression levels in each tissue correlated well. The results of phylogenetic and sequence identity analysis, immunological properties and tissue-distribution patterns of DNase I indicated a closer relationship between the rabbit and human enzymes than for other mammalian DNases I. Furthermore, differences between the enzymic activities expressed in mammalian parotid gland and pancreas suggest that the distribution of DNase I in mammalian tissue is species-specific.

Forensic applications of genetic polymorphisms detected in human body fluids (urine, semen and blood)

The development of a new genetic marker with forensic usefulness is difficult and costly work, but it is necessary. We discovered several new markers detected in urine, semen and blood. In particular, deoxyribonuclease I-polymorphism is one of the most useful markers for practical purposes, since it has a well-balanced gene frequency, high concentration in body fluids, stability against severe conditions, and easy and accurate detectability.

Ribonuclease inhibitors in human blood: comparative studies on the inhibitors detected in erythrocytes, platelets, mononuclear leukocytes and granulocytes

The erythrocyte ribonuclease inhibitor (RI) and platelet RI were separately purified to homogeneity and showed similar properties to those of human brain and placental RIs. The same type of RI seemed to be present in mononuclear leukocytes and granulocytes. The RI contents of these cells were detectable by immunoblot analysis using anti-human placental RI antibody. Neither RI activity nor the molecule cross-reactive with the anti-human placental RI antibody was detectable in any plasma sample. It is intriguing to detect active RI in mature erythrocytes, where no nucleus exists and RNA metabolism is unlikely to occur.

Use of antibodies against synthetic peptides for analysis of molecular multiplicity: human deoxyribonuclease I polymorphism

Eight different antibodies were raised in rabbits and chickens by injecting them with two synthetic N- and C-peptides, which corresponded to the N- and C-terminal 15 residues of human deoxyribonuclease I (DNase I). These two peptides were used as immunogens, both free and conjugated with keyhole limpet hemocyanin (KLH). A rabbit antiserum against the C-peptide conjugated with KLH (rabbit anti-C/KLH) and two chicken antisera against the C-peptide itself (chicken anti-C) and conjugated with KLH (chicken anti-C/KLH) reacted well with purified DNase I, blotted onto a transfer membrane after isoelectric focusing in a polyacrylamide gel. A clear isoenzyme pattern identical to that detected with a rabbit antiserum against the parent enzyme (rabbit anti-DNase I) was observed. Surprisingly, the chicken anti-C antiserum was found to be a powerful and highly specific tool for the determination of urinary DNase I phenotypes (Kishi et al., Hum. Genet. 1989, 81, 295-297) and was not inferior in any respect to the rabbit anti-DNase I. These findings show that the selection of immune animal is one of the most important factors for producing an effective anti-peptide antibody. Unfortunately, the anti-peptide antisera obtained in this study neither blocked DNase I enzyme activity nor did it bind to the enzyme.

Two distinct secretory ribonucleases from human cerebrum: purification, characterization and relationships to other ribonucleases

Two RNAases from human cerebrum were purified to an electrophoretically homogeneous state and their molecular masses were 22.0 kDa (tentatively called RNAase HB-1) and 19.0 kDa (RNAase HB-2). Analyses of the amino acid compositions, N-terminal amino acid sequences and catalytic properties of these enzymes provided strong evidence that they were strictly related to the secretory (sec) RNAases, such as the pancreatic enzyme, very similar immunologically to urinary sec RNAase, but clearly distinguishable from urinary non-secretory (nonsec) RNAase. There were several differences between HB-1 and HB-2, namely their immunological reactivities with specific antibodies, heat-stabilities, attached carbohydrate moieties and molecular masses. In particular, HB-2 appeared to be nonglycosylated, in view of its lack of affinity for several conjugated lectins, the absence of hexosamine and no change in electrophoretic mobility before and after peptide:N-glycosidase F digestion, whereas HB-1 and human sec RNAases purified from kidney, pancreas and urine all appeared to be glycosylated, as they moved to the same position as HB-2 when electrophoresed after glycosidase digestion. An antibody against urinary sec RNAase inhibited 75% and 20% of the total activity of the crude cerebral extract against RNA at pH 8.0 and 6.0 respectively, whereas an antibody against urinary nonsec RNAase had no such inhibitory effect. These findings suggest that yet another type(s) of cerebral RNAase, which is unable to cross-react immunologically with sec and nonsec RNAases, may exist. Two RNAases corresponding to HB-1 and HB-2 were identified in fresh cerebrospinal fluid.

The zymogram method for detection of ribonucleases after isoelectric focusing: analysis of multiple forms of human, bovine, and microbial enzymes

A zymogram method for detection of in situ ribonuclease (RNase) activity, combined with isoelectric focusing in a thin layer of polyacrylamide gel (IEF-PAGE), has been developed. After incubation with a dried agarose film containing substrate RNA, ethidium bromide, and an appropriate reaction buffer, which was placed tightly on the top of the focused gel, sharp and distinct dark bands corresponding to RNase isoenzymes on a fluorescent background appeared under uv light. Addition of urea to the IEF-PAGE gel at a final concentration of 4.8 M permitted optimal focusing of the RNases. This method had not only a high sensitivity of less than 0.1 ng purified RNase A, but also a high band resolution compared with the immunostaining method. It was also useful for analysis of purified enzymes, including bovine pancreatic RNases and two types of human urine RNase as mammalian enzymes, and RNases T1 and T2 as microbial enzymes, as well as for detection of RNases present in crude tissue extracts, resulting in more detailed elucidation of the multiplicity of these enzymes.

Specific identification of human ribonucleases by antibodies produced against two synthetic peptides corresponding to the N- and C-terminal amino-acid sequences of human urinary secretory-type ribonuclease

Antibodies were raised in rabbits by immunizing two synthetic peptides, which corresponded to the N- and C-terminal 15 residues, respectively, of human urinary secretory ribonuclease (RNase). These antibodies did not block the RNase activity, but reacted well with enzymes blotted onto a transfer membrane following electrophoresis, and discriminated strictly between secretory- and nonsecretory-type RNases. Therefore, these antibodies should to be valuable tools for the immunological identification of human RNases.

Human urine deoxyribonuclease II (DNase II) isoenzymes: a novel immunoaffinity purification, biochemical multiplicity, genetic heterogeneity and broad distribution among tissues and body fluids

Deoxyribonuclease II (DNase II) was purified from the urine of a 48-year-old male (a single individual) using a column chromatography series, including concanavalin A-agarose and an immunoaffinity column utilizing anti-human spleen DNase II antibody, and was then characterized. Based on the catalytic properties of the purified enzyme, we have devised a technique of isoelectric focusing by thin-layer polyacrylamide gel electrophoresis (IEF-PAGE) combined with a specific zymogram method, for investigating the possible molecular heterogeneity of human DNase II. DNase II in urine as well as the purified form was found to exist in multiple forms with different pI values separable by IEF-PAGE within a pH range of 5-7. Since sialidase treatment of the urine sample induced simplification of the isoenzyme patterns with diminishment of anodal bands, it was clear that the multiplicity of the enzyme was in part due to differences in the sialic acid content. On screening of DNase II isoenzyme patterns in urine samples from more than 200 Japanese individuals, only the common isoenzyme pattern was observed and no electrophoretic variations were detected. However, genetic studies of urinary enzyme activity and comparative studies on the activity in urine, semen and leukocytes from the same individuals suggest that the enzyme activity level of DNase II may be under genetic control. The enzyme was widely distributed in human tissues and showed high activities in secretory body fluids such as breast milk, saliva, semen and urine, and leukocyte lysates.

Cellular and tissue distribution of a single-strand-specific nuclease

1. Specific antibodies which were raised against a single-strand-specific nuclease isolated from rat liver microsomes were used for characterizing this enzyme and determining its cellular and tissue distribution. 2. The single-strand-specific nuclease does not show any homology with other known nucleolytic enzymes. 3. It is mainly localized in microsomes and cytosol; traces of it are also found in nuclei, but it could not be detected in mitochondria. 4. Using the same specific antibodies we attempted to detect this nuclease in some other tissues which exhibit high metabolic rates, namely kidneys, heart and spleen. 5. Thus, with the aid of immunological techniques we were able to determine that at least part of the total poly(U) nucleolytic activity observed in kidney and heart is due to a nuclease immunologically identical to the enzyme under study. Kidneys were the best source for this enzyme.

Intensification of peroxidase-diaminobenzidine staining using gold-sulfide-silver: a rapid and highly sensitive method for visualization in immunoblotting

A highly sensitive and rapid visualization method for protein detection by immunoblotting is described. Proteins blotted onto a Durapore membrane were visualized by the following procedure: after conventional peroxidase-based staining with 3,3'-diaminobenzidine (DAB), the produced DAB precipitates were intensified by treating with (i) gold trichloride (acid), (ii) sodium sulfide, and (iii) a developer containing silver nitrate. This postintensification method was employed for the detection of the genetic polymorphism of human proteins, such as deoxyribonuclease I in urine, and group specific component, transferrin and alpha 1-antitrypsin in serum after polyacrylamide gel-isoelectric focusing, followed by immunoblotting. This postintensification technique was found to be simple, giving up to 16- to 64-fold amplification of the conventional peroxidase-DAB staining.

Purification and characterization of three ribonucleases from human kidney: comparison with urine ribonucleases

Three ribonucleases (RNases) with different molecular masses were isolated from human kidney. The enzymes were purified to an electrophoretically homogeneous state, and their respective molecular masses were found to be 18,000 (tentatively named RNase HK-1), 20,000 (RNase HK-2A), and 22,000 (RNase HK-2B) on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Analysis of the amino acid compositions, amino-terminal sequences, and enzymological properties of the enzymes indicate that RNase HK-1 is related to "nonsecretory" RNase, and that RNases HK-2A and HK-2B are both related to "secretory" RNase. Furthermore, RNase HK-1 showed cross-reactivity with an antibody specific to nonsecretory RNase from human urine, whereas RNases HK-2A and HK-2B showed cross-reactivity with another antibody specific to human urine secretory RNase. However, the carbohydrate compositions of RNases HK-2A and HK-2B were markedly different from that of the secretory urine RNase. This finding seems to indicate that the kidney is not the origin of the urine enzyme.

GC polymorphism detected in human urine by isoelectric focusing and immunoblotting

Genetic polymorphism of GC (vitamin D-binding protein) in human urine was revealed by isoelectric focusing and immunoblotting on thin-layer polyacrylamide gels containing 2 M urea. Urine samples from 530 unrelated Japanese from the Fukui district, being only 1-2 ml of original urine, were examined, and correct GC typing was achieved by comparison with the results of direct grouping using plasma. Six common and twelve rare phenotypes were observed. The frequencies of the genes were 0.473 for GC*1F, 0.241 for GC*1S, 0.254 for GC*2, and 0.032 for the total of six rare alleles.

Purification and characterization of a ribonuclease from human spleen. Immunological and enzymological comparison with nonsecretory ribonuclease from human urine

A ribonuclease has been isolated from human spleen (RNase HS) by means of acid extraction, ammonium sulphate fractionation, successive column chromatographies on CM-cellulose, heparin-actigel, and poly(G)-agarose, and double gel-filtration on Sephadex G-75. The purified preparation was homogeneous as judged by SDS/PAGE. RNase HS was found to be a glycoprotein, containing three fucose, one mannose and five glucosamine residues/molecule, with a molecular mass of 17 kDa as determined by both SDS/PAGE and gel filtration. The catalytic properties and structural features, including its amino acid composition and the amino acid sequence of the N-terminal 35 residues, indicated that the enzyme was strictly related to nonsecretory RNase isolated from human urine and liver. In particular, the amino acid sequence of the N-terminal was identical with that of urine nonsecretory RNase and eosinophil-derived neurotoxin. Furthermore, analyses using three different antibodies specific to RNase HS, urine nonsecretory RNase and urine secretory RNase, indicated that RNase HS was not immunologically distinguishable from urine nonsecretory RNase, but clearly so from urine secretory RNase. However, the carbohydrate compositions of RNase HS and urine nonsecretory RNase were found to differ. It therefore remains to be resolved whether or not the tissue of origin of nonsecretory RNase in urine is the spleen.

Purification and characterization of two ribonucleases from human erythrocytes: immunological and enzymological comparison with ribonucleases from human urine

Two ribonucleases (RNases), one active against RNA as well as poly(C) and the other more markedly against poly(C), were isolated from human erythrocytes by acetone fractionation in the presence of 0.25 M H2SO4, followed by a series of column chromatographies. The purified enzymes appeared homogeneous as judged by sodium dodecyl sulfate--polyacrylamide gel electrophoresis (SDS-PAGE), and were tentatively designated RNase HE-1 and RNase HE-2. The content of RNase HE-1 in erythrocytes was much higher than that of RNase HE-2. The molecular mass of RNase HE-1 was determined to be 18,000 and 16,000 Da, and that of RNase He-2 39,000 and 31,000 Da, by SDS-PAGE and gel filtration, respectively. The catalytic properties and structural features of RNase HE-1 including the amino acid composition and N-terminal amino acid sequence indicated that its protein moiety is strictly related to a nonsecretory RNase purified from human urine (Yasuda et al., 1988, Biochim. Biophys. Acta 965, 185-195). In particular, the N-terminal amino acid sequence up to the 32nd residue was identical with that of urine nonsecretory RNase reported recently (Beintema et al., 1988, Biochemistry 27, 4530-4538). Furthermore, RNase HE-1 was immunologically indistinguishable from urine nonsecretory RNase, but clearly differed from urine secretory RNase. On the other hand, erythrocyte RNase HE-2 was enzymologically and immunologically similar to urine secretory RNase.

New detection method for ribonuclease 2 (RNase 2) using immunoblotting with specific antibody

A ribonuclease (RNase) was isolated from the urine of a 35-year-old male and purified to electrophoretic homogeneity. The enzyme was tentatively designated RNase 2. A rabbit antibody produced by injection of the purified RNase 2 was able to distinguish RNase 2 from another type of RNase coexisting in body fluids. With this antibody it was possible to detect RNase 2 isozymes in human serum and urine without difficulty using isoelectric focusing or sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by immunoblotting. Both RNase 2 in serum and urine seemed to exist in multiple forms with regard to their molecular masses and pI values. This technique may prove to be useful in genetic and forensic studies of RNase polymorphism.

Biochemical and genetic studies on GP43, a 43-kD glycoprotein detected immunologically in human urine and serum

A new and previously undescribed glycoprotein with a molecular weight of 43,000 has been isolated from human urine. This protein, designated GP43; copurified with ribonuclease, which has the same molecular weight, but ribonuclease activity was removed by passage through an affinity column of agarose-5'-(4-aminophenyl phosphoryl) uridine 2'(3') phosphate. GP43 contains about 5.9% neutral sugar, 2.3% hexosamine, and 1.6% sialic acid. A rabbit antibody to the purified GP43 reacted with human urine and serum as well as with the purified GP43. The genetic polymorphism of GP43 was then studied in desialylated human serum samples by urea-polyacrylamide gel isoelectric focusing, followed by immunoblotting with the specific antibody for GP43. Three common phenotypes, designated GP43 1, 1-2, and 2, were easily recognized using this technique and represented homozygosity or heterozygosity for two autosomal codominant alleles, GP43*1 and GP43/2. The frequencies of the GP43*1 and GP43*2 alleles in a Japanese population were 0.7683 and 0.2317, respectively.

Genetic analysis of human deoxyribonuclease I by immunoblotting and the zymogram method following isoelectric focusing

We have devised two independent detection methods for investigating possible molecular heterogeneity and genetic polymorphism in human DNase I, in terms of both its antigenicity and enzymatic activity. One was an immunoblotting method using an antibody specific to DNase I following polyacrylamide gel isoelectric focusing (IEF-PAGE). The DNase I-specific antibody was raised in a rabbit using purified enzyme from human urine as the immunogen. DNase I in urine was found to exist in multiple forms with different pI values separable by IEF-PAGE within a pH range of 3.5-4.0. This method was able to detect as little as 0.1 micrograms of the purified DNase I and facilitated classification of desialylated urine samples from different individuals into several groups according to differences in DNase I isozyme patterns. About 0.5 ml of the original urine was sufficient for analysis of the isozyme patterns. The other method was the zymogram method, which had a high sensitivity and resolution almost identical to those of the immunoblotting method for analysis of DNase I patterns. It was easier to perform, more time-saving, and more useful since it did not require antibody specific to DNase I. These two methods should prove valuable for biochemical and genetic analysis of DNase I isozymes.

A hereditary double double-banded variation in the vitamin D-binding protein (GC) system analyzed by immunoblotting: duplication of the 1F and 1A2 genes?

A combination of immunoblotting and polyacrylamide gel isoelectric focusing (IEF-PAGE) was used to define a new genetic variant in the (GC) group-specific component system. This appeared to be a GC 1-type variant, and was presumed to have arisen from duplication of the GC 1F and GC 1A2 genes.

Purification and properties of the age-related protein (ARPB) detected in human brain: comparison with human brain calmodulin

ARPB is an age-related protein in the human brain which is present in individuals younger than approximately 40 years of age, but disappears or becomes remarkably decreased in individuals above this age (Yasuda, T. and Kishi, K. (1985) Proc. Japan Acad. 61B, 273-276). ARPB was isolated from four different cerebra obtained from subjects 0, 15, 35 and 37 years old, and purified to an electrophoretically homogeneous state. Its molecular weight was estimated to be 17,000 and 36,000-38,000 by SDS-polyacrylamide gel electrophoresis and gel filtration, respectively. The amino acid composition of the purified ARPB, containing an excess of acidic amino acid residues (about 33%), proved to be very similar to that of calmodulin. ARPB exhibited some of the properties characteristic of calmodulin, such as a Ca2+-dependent mobility change upon electrophoresis, and activation of calmodulin-deficient phosphodiesterase activity in a Ca2+-dependent manner. However, it was possible to distinguish ARPB and human calmodulin with regard to their kinetic parameters for the activation reaction of phosphodiesterase activity, despite a close similarity in their reaction mode. It can be concluded that ARPB belongs to one of the calmodulin group proteins, although it remains unknown whether ARPB is identical to calmodulin.