Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Amylase from chicken pancreas was purified by an affinity method involving filtering a crude extract from pancreas through a Sepharose-wheat albumin column and eluting the retained enzyme with maltose. The purified amylase showed two active bands upon polyacrylamide electrophoresis in an alkaline buffer system and only one band in an acidic buffer system. The enzyme is a Ca2+-glycoprotein which behaves as a typical alpha-amylase. It consists of a single polypeptide chain with molecular weight 53,000 and contains 5.3 moles of reducing sugars per mole of protein. Optimal conditions of pH and temperature for the enzymic activity are 7.5 and 37 degrees C. The enzyme is irreversibly inactivated by removal of Ca2+ by exhaustive dialysis and is activated by the presence in the assay mixture of Cl-; other halides are less effective than Cl- in activating the enzyme.
Mol Cell Biochem 1977 Aug 19
PMID:Purification and properties of alpha-amylase from chicken (Gallus gallus L.) pancreas. 2 May 68

Angiotensin-converting enzyme from rabbit serum was purified almost 60,000-fold to apparent homogeneity by a procedure exploiting its affinity for antibodies prepared against the enzyme from lung. The pure serum and pulmonary enzymes exhibited identical behavior during gel filtration, sucrose gradient centrifugation, and disc gel electrophoresis in the reduced, denatured state. Their catalytic properties with hippurylhistidylleucine, angiotensin I, and bradykinin as substrates were similar and their reactivity with antilung enzyme antibody was indistinguishable as examined by immunodiffusion, inhibition dose-response curves, and radioimmunoassay. Their content of fucose, mannose, galactose, and N-acetylglucosamine was also comparable; however, N-acetylneuraminic acid was much more abundant in the serum glycoprotein. This difference may reflect selective removal of sialic acid-deficient enzyme molecules from the circulation by the hepatic lectin which has been postulated to initiate the catabolic phase for plasma glycoproteins (Ashwell, G., and Morell, A.G. (1974) Adv. Enzymol. Relat. Areas Mol. Biol. 41, 91-128).
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PMID:Serum angiotensin-converting enzyme. Isolation and relationship to the pulmonary enzyme. 19 Feb 28

Mucolipidosis II (I-cell disease) and Mucolipidosis III (ML III) are inherited disorders in which the molecular defect may involve an abnormality in a common post-translational modification step (possibly glycosylation) shared by lysosomal hydrolases. We tested whether such an alteration might be a generalized defect in glycoprotein biosynthesis and, thus, be reflected in an abnormal carbohydrate composition of non-lysosomal glycoproteins. The apoprotein of low density lipoprotein (apo-LDL) and immunoglobulin G (IgG) were purified to apparent homogeneity. Gas liquid chromatographic (glc) analysis of the carbohydrate content of these glycoproteins from ML II, ML III and normal sera revealed no differences in the relative ratios and total amounts of mannose, galactose, N-acetylglucosamine and sialic acid. These results suggest that if the postulated post-translational defect in these disorders involves changes in carbohydrate composition, it is not a general defect in glycosylation and may be specific for lysosomal hydrolases.
Mol Cell Biochem 1978 Oct 13
PMID:Carbohydrate composition of purified serum glycoproteins in mucolipidosis II and mucolipidosis III. 21 98

This review summarizes some recent studies on the surface glycoproteins of human thymocytes and T lymphocytes. Purified cells were surface labeled by the galactose oxidase-NaB3H4 or periodate-NaB3H4 techniques. The radioactive membrane glycoproteins were separated by polyacrylamide slab gel electrophoresis and visualized by fluorography. Thymocytes and T lymphocytes show characteristic surface glycoprotein profiles which are easily distinguishable from those of the other main groups of human leukocytes. We observed specific changes in the surface glycoprotein patterns which correlate with the degree of maturation and functional activation of T cells. Surface molecules carrying T cell specific antigens were identified by immune-precipitation from lysates of surface labeled thymocytes and T lymphocytes using rabbit anti-human T cell antibodies. Finally we describe a leukocyte membrane glycoprotein which is a precursor of serum alpha 1 acid glycoprotein (orosomucoid).
Mol Cell Biochem 1979 Oct 15
PMID:Surface glycoproteins of resting and activated human T lymphocytes. 31 14

Complex of ovomucoid with 1,2 dihehadecyl-snglycero-3-phosphatidylcholine (DHPC) in water solution has been used as a model system for glycoprotein-lipid interactions. The structural parameters of this complex were determined with small angle-X-ray diffraction techniques. Knowing the repeat distance, the chemical composition of the association and the partial specific volumes of the components, the partial thickness of the glycoprotein, lipid and water layers can be determined and compared with the thickness of the lipid layers observed in pure lipid-water systems and lamellar associations in the absence of glycoprotein. The variation of the structural parameters at room temperature with the concentration of water was determined. Our results showed: the intersheet spacing increases from 112 to 157 A, the thickness of the hydrocarbon chain layers decreases from 49 to 40A and the thickness of glycoprotein layer increases from 62 to 100 A. In this case the glycoprotein-lipid interaction appears to be of weak electrostatic nature and to involve mainly the polar regions of the structure. Fluorescence experiments have also been carried out to confirm the X-ray data.
Mol Biol Rep 1979 Aug 31
PMID:X-ray studies of the ovomucoid-DHPC system. 49 59

1. Two different molecular forms of dopamine-beta-hydroxylase were isolated from human serum; a major component (Peak I enzyme) with a molecular weight of 368000 and with a higher specific activity and a minor component (Peak II enzyme) with a molecular weight of 188000 and with a lower specific activity. 2. Both forms require ascorbic acid for the activity, and are stimulated by fumarate. Addition of N-ethylmaleimide or copper also increased the activity. The optimal pH of both forms in the presence of 20mM tyramine as substrate is 5.0. 3. Km values toward tyramine of Peak I enzyme and Peak II enzyme were 1.67 mM and 14.2 mM respectively. 4. Both Peak I enzyme and Peak II enzyme are glycoprotein.
Mol Cell Biochem 1977 Dec 29
PMID:Purification and properties of human serum dopamine-beta-hydroxylase. 56 50

The prostate glands of rats, mice, guinea pigs and hamsters were found to be a rich source of enzymes catalyzing the Mn2+-dependent transfer of galactose from UDP-galactose to glycoprotein acceptors such as ovomucoid and ovalbumin. The ventral prostate was also very active in promoting transfer of fucose from GDP-fucose to ovomucoid. The prostatic enzymes promoting both galactosyl and fucosyl transfers to glycoproteins were very largely membrane-bound, and were markedly activated by the non-ionic detergent Triton X-100. Castration of adult male resulted in a many-fold and roughly parallel decline in both glycosyltransferase activities over a period of two weeks, which was reversed by subsequent daily treatment with testosterone for 8 days. The very low galactosyltransferase of the ventral prostate of hypophysectomized rats was markedly enhanced by testosterone administration, whereas prolactin alone or in combination with androgen had no significant effect.
Mol Cell Endocrinol
PMID:Glycoprotein glycosyltransferases in male reproductive organs and their hormonal regulation. 82 97

1. A quantitative radioimmunoassay was developed for the measurement of nanogram amounts of Tamm-Horsfall (TH) glycoprotein in the presence of serum proteins at concentrations above 30 mg/ml. 2. Specific anti-(TH-glycoprotein) antibodies were labelled with 125I and these were usable for a period of 8 weeks. 3. Agarose beads (Sepharose 4B), to which TH-glycoprotein had been coupled via cyanogen bromide activation of the Sepharose, were used as the solid phase in the assay. This proved stable upon storage at 4 degrees C for periods in excess of 4 months. 4. The dissociation of the glycoprotein in the presence of serum proteins that was necessary for quantification was achieved by subjecting the sample to ultrasonication. 5. Assays conducted on a small sample of normal serum produced evidence that normal serum contained amounts (50-180 ng/ml) of a substance that reacted similarly to TH-glycoprotein in the assay procedure and in a series of experiments conducted to confirm the presence of this substance in human serum.
Clin Sci Mol Med 1977 Feb
PMID:The development of a radioimmunoassay procedure for the estimation of Tamm-Horsfall glycoprotein in human serum. 84 51

Nephrectomy of mature rats was found to result in a significant increase in the circulatory half-life of tritiated ovine lutropin. The interaction of the glycoprotein hormone with the kidneys was studied in a more direct fashion using electron microscopic autoradiography. Evidence is presented showing the transfer of the hormone from microvilli into tubular epithelia (probably via vesicular transport), where radioactivity then becomes associated with lysosomes. This provides direct support for related results based on subcellular fractionation in which renal lysosomal catabolism was suggested as being important in the degradation of tritiated lutropin (M. Ascoli, R. A. Liddle, and D. Puett, Molecular and Cellular Endocrinology 4, 297, 1976). These results add substantial weight to the growing evidence that the kidneys assume a major role in controlling the concentration of circulating macromolecules.
Mol Cell Biochem 1977 Mar 21
PMID:Renal uptake of lutropin. Studies based on electron microscopic autoradiography and nephrectomy. 86 84

Highly purified plasma membranes were obtained from isolated porcine thyroid cells maintained in conditions of culture in the presence of thyrotropin (stimulated cells) or in their absence (non-stimulated cells). Analyses of both types of membranes by high-resolution sodium dodecylsulfate-polyacrylamide slab gel electrophoresis showed reproducible quantitative differences in protein bands of apparent molecular weight 38,000, 36,000 and inconstantly 96,000. Phosphorylation of membranes by [gamma-32P]ATP was 2-3 times higher in membranes from thyrotropin-stimulated than in membranes from non-stimulated cells. About 20 32P-labeled bands were detected by slab gel electrophoresis in denaturing conditions, among which the catalytic subunit of Na+, K+ ATPase was characterized. In addition, plasma membranes from thyrotropin-stimulated cells contained a firmly bound [14C]glucosamine-containing glycoprotein probably related to an aggregation-promoting factor. 125I-labeled thyroglobulin and components of unknown nature were associated with plasma membranes from thyrotropin-stimulated cells. Whether they participate in the structure and function(s) of the plasma membrane or represent contaminants of the preparation is not clear at the present time.
Mol Cell Endocrinol 1977 Jun
PMID:Thyrotropin-induced plasma membrane protein modifications in porcine thyroid cells. 88 86


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