A Submicrodetermination of Glucose

Park, James T.; Johnson, Marvin J.

doi:10.1016/s0021-9258(18)56635-7

Cited by 1,491 publications

(110 citation statements)

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“…Peptidoglycan (1.5 mg) from E. coli BE was dispersed in 1.7 ml of 0.02 M sodium 2-(N-morpholino)ethanesulfonate (MES-Na), pH 5.8, with a Branson W185 Sonifier (40 W, 30 s) and mixed with 0.1 ml of an enzyme solution (1.8 U). The determination of reducing groups in the reaction mixture was carried out according to the Park-Johnson procedure (20), with N-acetylmuramic acid as a standard, ranging from 10 to 50 nmol. Free amino groups were determined by dini with L-alanine as a standard, ranging from 1( Another mixture was prepared as above anm at 37°C for 4 h. The enzyme digest (1.5 mg oi was reduced with 2 mg of NaBH4 (0.1 ml aqueous solution) at 37°C for 48 h after the a( of Na2CO3 (0.1 ml of a 100-mg/ml solution) dryness, and then hydrolyzed with 1 ml of 6 M HCI at 105°C for 24 h. The components having amino groups in the hydrolysate were analyzed with a Hitachi KLA-3B amino acid analyzer.…”

mentioning

confidence: 99%

Isolation and characterization of the bacteriophage T4 tail-associated lysozyme

Nakagawa¹,

Arisaka²,

Ishii³

1985

J Virol

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Direct evidence has been obtained that the tail-associated lysozyme of bacteriophage T4 (tail-lysozyme) is gp5, which is a protein component of the hub of the baseplate. Tails were treated with 3 M guanidine hydrochloride containing 1% Triton X-100, and the tail-lysozyme was separated from other tail components by preparative isoelectric focusing electrophoresis as a peak with a pI of 8.4. The molecular weight as determined from sodium dodecyl sulfate electrophoresis was 42,000. The tail-lysozyme was unambiguously identified as gp5 when the position of the lysozyme was compared with that of gp5 of tube-baseplates from 5ts1/23amH11/eL1ainfected Escherichia coli cells by two-dimensional gel electrophoresis. The tail-lysozyme has N-acetylmuramidase activity and the same substrate specificity as gene e lysozyme; the optimum pH is around 5.8, about 1 pH unit lower than for the e lysozyme. We assume that the tail-lysozyme plays an essential role in locally digesting the peptidoglycan layer to let the tube penetrate into the periplasmic space. The tail-lysozyme is presumably also responsible for "lysis from without."

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confidence: 99%

Isolation and characterization of the bacteriophage T4 tail-associated lysozyme

Nakagawa¹,

Arisaka²,

Ishii³

1985

J Virol

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“…Amylase was tested at 0.2 M citrate/phosphate buffer pH 7.0 with 5% starch solution as substrate and 0.5% NaCl (Bernfeld, 1955) in 0.2 M citrate/phosphate buffer pH 7.0 with 5% starch solution as substrate and 0.5% NaCl at 25°C for 35 min and interrupted by the addition of 5% ZnSO 4 -Ba(OH) 2 . Subsequently, it was centrifugated at 1000 × g for 3 minutes and the reaction product was read at 690 nm (Park and Johnson, 1949).…”

Section: Enzymes Assaymentioning

confidence: 99%

Influence of a Blend of Dietary Essential Amino Acids on Growth, Enzymatic Activity, and Intestinal Histology of Blue Discus

Santos¹,

Siqueira²,

Reis³

et al. 2021

Bol. Inst. Pesca

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Symphysodon aequifasciatus is a fish with a disk-shaped body and bright colors, important characteristics of ornamental fish. We evaluated amino acid supplementation strategies to reduce crude protein in the diet for evaluation of performance, the content of digestive enzymes, liver metabolism, and intestinal histopathology. A total of 180 fish were randomly distributed in 12 separate 50 L glass aquariums, consisting of a completely randomized design with four treatments (DC - Control diet with 34.4% crude protein; DL - Control diet plus 1% of lysine; DEAA - Control diet plus 1% free essential amino acids (threonine, phenylalanine, leucine, valine, arginine, and tryptophan); and DHP - Diet with a high level of crude protein 48.4%), three repetitions, lasting 60 days. The use of DL and DEAA diets resulted in higher intestinal villus height and higher zootechnical performance. The use of DL diet increased alkaline phosphatase and digestive amylase activity. The use of DHP diets promotes severe liver changes due to increased activity of Alanine aminotraserase. Therefore, it was possible to observe that the use of amino acids can supply the nutritional need of blue discus. Supplementation of diets with AAs allows the reduction of dietary protein, which is a strategy for feeding management.

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“…Purified peptidoglycan (Park & Hancock, 1960) was used as the substrate in the investigation of enzyme specificity. Amino or aldehyde groups possibly released by enzymic action were detected by standard procedures (Habeeb, 1966;Park & Johnson, 1949). Hexosamine analysis (Fauconnet & Rochemont, 1978) was carried out with a Multichrome B Beckman Analyzer, after reduction (with 25 mM-NaBH4) and acid hydrolysis (in 4.2M-HCl for 8h at 1050C) of the enzymic reaction products.…”

Section: Enzyme Activity Measurementsmentioning

confidence: 99%

“…Hexosamine analysis (Fauconnet & Rochemont, 1978) was carried out with a Multichrome B Beckman Analyzer, after reduction (with 25 mM-NaBH4) and acid hydrolysis (in 4.2M-HCl for 8h at 1050C) of the enzymic reaction products. Chitinase activity was detected by the titration of reducing groups (Park & Johnson, 1949) released from colloidal chitin (Jeuniaux, 1966). The synthetic substrates p-nitrophenyl 2-acetamido-2-deoxy-/1-Dglucopyranoside, p-nitrophenyl 2-acetamido-2deoxy-fJ-D-galactopyranoside (Koch-Light, Colnbrook, Bucks., U.K.) and N-acetyl-fl-D-glucosamine naphthol AS-LC (Sigma, St. Louis, MO, U.S.A.) were used to detect non-lysozymic fl-hexosaminidase activities in the course of purification.…”

Section: Enzyme Activity Measurementsmentioning

confidence: 99%

Calf rennet lysozyme

Pahud¹,

Widmer²

1982

Biochemical Journal

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A glycosidase displaying endo-N-acetylmuramoylhydrolase specificity (EC 3.2.1.17) was isolated from calf rennet. This lysozyme was also present in abomasal secretions from calf and adult cattle. Multiple molecular forms revealed by electrofocusing might be artefacts. The main enzyme form had Mr approx. 15 000, pH optimum 5.0, pI7.5, and a remarkable conformation stability. Competitive inhibition was observed with both N-acetylglucosamine and N-acetylmuramic acid, with apparent Ki values of 29 mM and 2.4 mM respectively. The isolated enzyme also displayed significant chitinase activity.

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A Submicrodetermination of Glucose

Cited by 1,491 publications

References 3 publications

Isolation and characterization of the bacteriophage T4 tail-associated lysozyme

Isolation and characterization of the bacteriophage T4 tail-associated lysozyme

Influence of a Blend of Dietary Essential Amino Acids on Growth, Enzymatic Activity, and Intestinal Histology of Blue Discus

Calf rennet lysozyme

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