Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0519030 (Klebsiella)
 21,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A simplified procedure for the preparation of 1,4-alpha-glucan phosphorylase from Klebsiella pneumoniae is described. An 80-fold purification is achieved in two steps with an overall yield of about 50%. The specific activity of the homogeneous enzyme protein is 17.7 units/mg. Compared with glycogen phosphorylase from rabbit muscle the enzyme from K. pneumoniae shows a markedly higher stability against deforming and chaotropic agents. The 1,4-alpha-glucan phosphorylase was covalently bound to porous glass particles by three different methods. Coupling with glutaraldehyde gave the highest specific activity, i.e., 5.6 units/mg of bound protein or 133 units/g of glass with maltodextrin as substrate. This corresponds to about 30% of the specific activity of the soluble enzyme. With substrates of higher molecular weight, such as glycogen or amylopectin, lower relative activity was observed. The immobilized enzyme preparations showed pH activity profiles which were slightly displaced to higher values and exhibited an increased temperature stability.
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PMID:1,4-alpha-Glucan phosphorylase form Klebsiella pneumoniae covalently couple on porous glass. 1 12

Glycogen debranching enzyme (GDE) degrades glycogen in concert with glycogen phosphorylase. GDE has two distinct active sites for maltooligosaccharide transferase and amylo-1,6-glucosidase activities. Phosphorylase limit dextrin from glycogen is debranched by cooperation of the two activities. Fluorogenic branched dextrins were prepared as substrates of GDE from pyridylaminated maltooctaose (PA-maltooctaose) and maltotetraose, taking advantage of the synthetic action of Klebsiella pneumoniae pullulanase. Their structures were as follows: Glcalpha1-4Glcalpha1-4Glcalpha1-4Glcalpha1-4Glcalpha1-4(Glcalpha1-4Glcalpha1-4Glcalpha1-4Glcalpha1-6)Glcalpha1-4Glcalpha1-4GlcPA (B3), Glcalpha1-4Glcalpha1-4Glcalpha1-4Glcalpha1-4(Glcalpha1-4Glcalpha1-4Glcalpha1-4Glcalpha1-6)Glcalpha1-4Glcalpha1-4Glcalpha1-4GlcPA (B4), Glcalpha1-4Glcalpha1-4Glcalpha1-4(Glcalpha1-4Glcalpha1-4Glcalpha1-4Glcalpha1-6)Glcalpha1-4Glcalpha1-4Glcalpha1-4Glcalpha1-4GlcPA (B5), Glcalpha1-4Glcalpha1-4(Glcalpha1-4Glcalpha1-4Glcalpha1-4Glcalpha1-6)Glcalpha1-4Glcalpha1-4Glcalpha1-4Glcalpha1-4Glcalpha1-4GlcPA (B6), Glcalpha1-4(Glcalpha1-4Glcalpha1-4Glcalpha1-4Glcalpha1-6)Glcalpha1-4Glcalpha1-4Glcalpha1-4Glcalpha1-4Glcalpha1-4Glcalpha1-4GlcPA (B7), and Glcalpha1-4Glcalpha1-4Glcalpha1-4Glcalpha1-6Glcalpha1-4Glcalpha1-4Glcalpha1-4Glcalpha1-4Glcalpha1-4Glcalpha1-4Glcalpha1-4GlcPA (B8). These dextrins were incubated with porcine skeletal muscle GDE. No fluorogenic product was found in the digest of B8. The fluorogenic products from B3, B4, and B5 were PA-maltooctaose only. PA-maltooctaose, PA-maltoundecaose, and 6(7)-O-alpha-glucosyl-PA-maltooctaose were from B7. PA-maltooctaose and 6(6)-O-alpha-glucosyl-PA-maltooctaose were from B6. These results indicate that the maltooligosaccharide transferase removed the maltotriosyl residues from the maltotetraosyl branches by hydrolysis or intramolecular transglycosylation to expose 6-O-alpha-glucosyl residues, and then the amylo-1,6-glucosidase hydrolyzed the alpha-1,6-glycosidic linkages of the products rapidly. Probably, 6-O-alpha-glucosyl-PA-maltooctaoses from B7 and B6 were less susceptible to the amylo-1,6-glucosidase than were those from B3, B4, and B5. Taking this into account, B3, B4, and B5 are suitable substrates for GDE assay.
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PMID:Fluorogenic substrates of glycogen debranching enzyme for assaying debranching activity. 1584 May 1