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A Blank

Publications and source records attributed to A Blank.

At least 73 records · Page 4Linked to original sources
PubMed1981

Ribonucleases of human serum, urine, cerebrospinal fluid, and leukocytes. Activity staining following electrophoresis in sodium dodecyl sulfate-polyacrylamide gels.

The ribonucleases (RNases) of human blood serum, urine, cerebrospinal fluid (CSF), and leukocytes were visualized by activity staining after electrophoresis in RNA-case sodium dodecyl sulfate-polyacrylamide gels. Samples were prepared for electrophoresis by heating for 2 min at 100 degrees C in 2% sodium dodecyl sulfate (NaDodSO4) and 5% mercaptoethanol, conditions which dissociate proteins into their constituent polypeptide chains and permit estimation of molecular weight. It was found that each of the five peaks of serum alkaline RNase activity separable on phosphocellulose columns, i.e., RNases 1-5 of Akagi et al. [Akagi, K., Murai, K., Hirao, N., & Yamanaka, M. (1976) Biochim. Biophys. Acta 442, 368-378], is associated with electrophoretically distinct enzymes. The molecular weights exhibited by these enzymes in NaDodSO4 gels are 31 000 and 28 000 (major species of RNase 1), 25 000 (RNase 2), 20 000 (RNase 3), 16 000 (RNase 4), and 14 000 (RNase 5). The RNase activity of leukocytes displays a molecular weight of 17 000 and exhibits a characteristic dependence of its Rf on the temperature at which samples (in 2% NaDodSO4 without mercaptoethanol) are prepared for electrophoresis. An RNase activity like that of leukocytes, distinct from RNases 1-5, is found in serum. Urine RNase activity is less heterogeneous than that of serum, consisting mainly of species like serum RNase 1 and an enzyme similar to leukocyte RNase. Conversely, CSF RNase activity is more complex and includes enzymes resembling serum RNases 1-5 as well as additional species either not observed in serum or detected in serum as minor components following chromatography. The analytical methods described herein are particularly useful for assessment of heterogeneity of RNase preparations and for direct comparison of the RNases of crude and purified samples.

Electrophoresis, Polyacrylamide Gel↗
PubMed1981

Multiple ribonucleases of human urine.

Four major urine ribonuclease (RNase) activities, designated bands A-D, were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and activity staining. Bands A, B, and C have alkaline pH optima and display molecular weights of 31 000, 23 000, and 20 000, respectively, upon sodium dodecyl sulfate (NaDodSO4) gel electrophoresis and weights of 44 000, 28 000, 22 000 upon gel filtration. Band D, with a pH optimum slightly below neutrality, has a molecular weight of 16 000 or 15 000, respectively, determined by the above methods. Band A, the most abundant activity in urine, is heterogeneous and resembles serum RNase 1 on electrophoresis and on phosphocellulose and Sephadex chromatography. Band B is similar to a minor, unnamed component of serum RNase activity while band C resembles serum RNase 3. Band D is similar to the leukocyte RNase-like activity of serum [Blank, A., & Dekker, C.A. (1981) Biochemistry (preceding paper in this issue)]. Band A is present in urine at a concentration high than that of RNase 1 in serum. In contrast, urine counterparts of serum RNases 2, 4, and 5 are not apparent upon either phosphocellulose chromatography [see also Yamanaka, M., Akagi, K., Murai, K., Hirao, N., Fujimi, S., & Omae, T. (1977) Clin. Chim. Acta 78, 191-201] or NaDodSO4 get electrophoresis; a urine counterpart of serum RNase 3 can be detected only by the more sensitive electrophoretic method. These results indicate that RNase 2-5 are processed differently by the kidney than RNase 1. After reconciliation of reported differences in their pH optima and molecular weights, five apparently diverse RNase preparations described in the literature can be related to band A activity and three preparations to band D. However, we are unable to confirm a previous report of a human urine enzyme indistinguishable from bovine pancreatic RNase A.

Electrophoresis, Polyacrylamide Gel↗
PubMed1981

Nemaline myopathy and a mitochondrial neuromuscular disorder in one family.

A family composed of parents and four children is reported. Two brothers presented from early infancy with hypotonia and non-progressive weakness. Muscle biopsy in both revealed numerous typical nemaline rods. The father, suffering from backache, had a slow MNCV of both common peroneal nerves. His muscle revealed variation in fiber size, splitting, type 1 atrophy and numerous pleomorphic mitochondria with crystalline inclusions. The mother's muscle showed type 2 atrophy, foci of myofibrillar degeneration, and lipofuscin bodies. In a 12-year-old daughter and a 5-year-old son the muscle revealed an excess of small, bizarre mitochondria and lipid droplets. The coexistence of nemaline myopathy and a mitochondrial neuromuscular disorder in one family has never been reported in the literature. It might be a coincidence of two rare muscle disorders in one family, or it might be the polymorphic expression of a single etiological factor causing a defect in protein synthesis.

Adult↗
PubMed1981

Human body fluid ribonucleases: detection, interrelationships and significance.

Study of the RNases of human body fluids has been facilitated by use of activity staining following SDS-polyacrylamide gel electrophoresis. Commercial SDS preparations contain minor lipophilic contaminants (less than 0.1%) which interfere with enzyme renaturation and prevent activity staining unless gels are washed after electrophoresis in 25% isopropanol. Partial characterization of the RNases of serum, urine, and cerebrospinal fluid (CSF) is described, including evidence that the RNases comprising bands A-C of urine and 1-3 of CSF are glycoproteins. Evidence is presented that the major RNase activities of serum (RNases 1-5) and urine (band A) do not originate in pancreas, and that leukocytes are the source of band D RNase of urine, as well as of minor RNase activities of serum and CSF. Results are summarized suggesting that elevated plasma RNase levels may be of dubious utility in the diagnosis of most malignant diseases. Some elevated levels reported in the literature may reflect the advanced age of cancer patients, negative nitrogen balance, and other secondary effects of diseases, particularly kidney dysfunction.

Clinical Enzyme Tests↗
PubMed1981

Recovery after muscular fatigue in hemiparesis.

Setchenov showed in 1903 that the amount of work he could perform with his right arm after a pause, during which he had worked with his nonfatigued left arm was greater than if he had rested passively between bouts. Asmussen and Mazin have shown that recuperation after local muscle fatigue was influenced by a central nervous factor. In this paper 10 stroke patients were examined and the muscular activity of the deltoid was measured by means of EMG. The intact deltoid behaved according to Setchenov's observation. In 4 patients the diverting activity did not have any beneficial effect on the paretic muscle. It is assumed that in some of the stroke patients the brain damage affects the facilitatory centers which are needed for the recuperation after muscular fatigue.

Aged↗
PubMed1975

Differential activity staining: its use in characterization of guanylyl-specific ribonuclease in the genus Ustilago.

Guanylyl-specific ribonuclease can be identified by a novel technique employing electrophoresis in polyacrylamide slabs followed by differential activity staining. The technique requires as little as 7 ng of enzyme which may be grossly admixed with contaminants, including other ribonucleases. Upon electrophoresis and activity staining, a variety of ribonucleases can be visualized as light or clear bands in a colored background formed by toluidine blue complexed with oligonucleotide substrate. Guanylyl-specific ribonuclease, which is detectable when using an oligonucleotide substrate of random base sequence, does not yield a band when using oligonucleotides bearing guanylyl residues at the 3'-termini only and containing, therefore, no susceptible internucleotide bonds; in contrast, a ribonuclease with a different base specificity or no base specificity yields a band with either substrate. This differential activity staining method for establishing guanylyl specificity permits estimation of the extent of nonspecific cleavage of internucleotide linkages by a putatively guanylyl-specific enzyme and is at least as sensitive as conventional procedures for determination of base specificity. With this new technique guanyloribonuclease has been identified in the unfractionated culture medium of 10 organisms belonging to the phytopathogenic fungal genus Ustilago. It is suggested that guanylyl-specific ribonuclease is widely distributed among Ustilago species; its electrophoretic properties may be revealing of phylogenetic relationships among these plant parasites and among their hosts. The general technique of differential activity staining, developed for determination of the base specificity of ribonucleases, may be widely applicable to analysis of enzymes catalyzing depolymerization reactions.

Basidiomycota↗