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Y H Tan

Publications and source records attributed to Y H Tan.

133 records · Page 8Linked to original sources
PubMed1968

Canine submandibular-gland hyaluronidase. Identification and subcellular distribution.

1. Submandibular glands from four species of mammal have been shown to contain a hyaluronidase active at acid pH; glands from dog and cat had a much higher content of this enzyme than has been found in other sources. 2. Product formation from hyaluronate after 24hr. incubation was almost the same as with testicular hyaluronidase, indicating that the enzyme is an endo-poly-beta-hexosaminidase. 3. When submandibular-gland homogenates were fractionated by the scheme developed for liver by de Duve, Pressman, Gianetto, Wattiaux & Appelmans (1955), all the enzymes assayed, except cytochrome c oxidase, were found to occur partly in the soluble fraction and partly in the particulate fractions. Among the particular fractions, the highest specific activity was found in the heavy-mitochondrial fraction for cytochrome c oxidase, in the microsomal fraction for alkaline phosphatase and in the light-mitochondrial fraction for acid phosphatase, beta-N-acetylhexosaminidase and acid-active hyaluronidase. 4. Release of the enzyme activity from the sedimentable fractions occurred in 0.1% Triton X-100 or after high-speed homogenization. 5. Stimulation of dogs by pilocarpine was found to decrease the hyaluronidase content of the submandibular gland by 5% and to cause the occurrence of a corresponding amount of acid-active hyaluronidase in the submandibular saliva. 6. The results are discussed in relation to the subcellular localization of hyaluronidase.

Acid Phosphatase↗
PubMed1968

Canine submandibular-gland hyaluronidase. Purification and properties.

1. Methods for the purification of dog submandibular-gland hyaluronidase from sedimentable and non-sedimentable portions of a homogenate and from the whole homogenate are presented. The method consists of three main steps: removal of mucin by acid precipitation or gel filtration on Sephadex G-200, ammonium sulphate precipitation and CM-cellulose chromatography. By this method specific activities of up to 1.28 and 0.78mumoles of N-acetylglucosamine/min./mg. of protein were obtained for the purified freeze-dried non-sedimentable hyaluronidase and for the sedimentable hyaluronidase respectively. 2. A comparison of some of the properties of the non-sedimentable and the sedimentable hyaluronidase preparation indicated that there was little difference between the two and that they both resembled lysosomal hyaluronidase from rat liver.

Animals↗
PubMedDate not supplied

Analysis of cellular phosphoproteins by two-dimensional gel electrophoresis: applications for cell signaling in normal and cancer cells.

Two-dimensional (2-D) gel electrophoresis has been used to map proteins from various cell types in an effort to eventually link such maps to the sequencing of the entire human genome. While this analysis indicates the cellular disposition and expression of proteins, another application of 2-D gels, the analysis of phosphoproteins, can provide much information as to the assembly and "wiring" of the signal transduction circuits within cells which appear to be enervated by phosphate exchange. The preparation and separation of 32P-labeled proteins is described, as well as various analytical methods, including: the variety of gel systems available for specialist types of analyses, comparing 33P- and 32P-labeling of proteins, imaging techniques, phosphoamino analysis, phosphopeptide separation, identifying the amino acid groups that are phosphorylated, and the identification of phosphoproteins on 2-D gels by immunoprecipitation, corunning of purified proteins, comparative mapping and microsequencing, and by Western blotting. Examples (in brackets) are given of applications in which 2-D phosphogels can be applied, which offer advantages over other techniques. These include: (i) identifying in vivo substrates for kinases (protein kinase C activated by phorbol myristate acetate), (ii) investigating cytokine signaling pathways (tumor necrosis factor and interleukin-1), (iii) investigating the effects of drugs on signaling pathways (okadaic acid, menadione and cyclooxygenase inhibitors), (iv) characterization of specific phosphoproteins (heat-shock protein Hsp27 and stathmin), (v) comparing normal and transformed cells (MRC-5 human lung fibroblasts and their SV-40-transformed counterparts, MRC-5 SV1 cells), (vi) purifying phosphoproteins, (vii) investigating the relationship of protein phosphorylation to stages in the cell cycle (stathmin), (viii) investigating protein/protein interactions, (ix) mapping in vitro kinase substrates (protein kinase C, protein kinase A, and mitogen activated protein kinase activated protein kinase 2), and (x) locating and identifying cellular phosphatases (Hsp27 phosphatase). It is possible that the mapping of phosphoproteins can be linked to other 2-D gel databases and that information derived from these can be used in the future to better understand the signaling mechanisms of normal and cancerous cells.

Amino Acid Sequence↗