Isolation and partial identification of a pancreatic colipase

Maylié, M.F.; Charles, M.; Gache, Christian; Desnuelle, P.

doi:10.1016/0005-2795(71)90347-3

Cited by 158 publications

(27 citation statements)

References 6 publications

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“…Der Grund hierfür kann in dem verwendeten Colipasepräparat zu suchen sein. Aus Schweinepankreas sind mehrere verschieden große Proteine mit Colipaseaktivität dargestellt worden (20), im Pankreassekret findet sich eine Vorstufe (Pro-Colipase) (25). Die reproduzierbare Isolierung eines Colipasepräpa-rats mit definierter Aktivität ist offenbar nicht unproblematisch (15,25).…”

Section: Materials Und Methodenunclassified

Katalytische Aktivität der Serumlipase im kontinuierlichen titrimetrischen Test in Abhängigkeit von der Temperatur

Rick¹,

Hockeborn²

1984

Clinical Chemistry and Laboratory Medicine

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The effect of temperature on the catalytic activity of serum lipase in the continuous titrimetric assay Summary:The catalytic activity of the pancreatic lipase in serum was measured between 20 °C and 37 °C by the continuous titrimetric assay. As the temperature was increased, the time course of Substrate hydrolysis showed an increasing tendency to becorne non-linear. The degree of non-linearity and its time of onset depended on the sample, the volurne of sefurn in the assay, and the composition of the triglyceride Substrate mixture. Twenty seven series of investigations between 20 °C and 32 °C (maximal) showed a Q !0 value of l .45 (s = 0.03) and ari activation energy of = 27.42 ± 0.565 kJ/mol (6550 ± 135 cal/mol; ± s).At low assay temperature, the addition of colipase caused a slight deterioration of the reaction kinetics, whereas at higher temperatüres it caused a marked improvement in the time course of Substrate hydrolysis. We were unable, however, to identify a fixed colipase concentration that would promote a linear reaction irrespective of sample origih and Volume.

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Section: Materials Und Methodenunclassified

Katalytische Aktivität der Serumlipase im kontinuierlichen titrimetrischen Test in Abhängigkeit von der Temperatur

Rick¹,

Hockeborn²

1984

Clinical Chemistry and Laboratory Medicine

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“…It has been reported that cyclic adenosine 3',5'-monophosphate phosphodiesterase from animal tissues (6,7,9) and pancreatic lipase (3,8,14) are associated with protein activators. These activators were separated from the enzyme on DEAEcellulose chromatography (8,10,12,22).…”

Section: Discussionmentioning

confidence: 99%

Properties of a Protein Activator of NAD Kinase from Plants

Muto¹,

Miyachi²

1977

Plant Physiol.

107

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Purification of pea (Pisum sativum) seedling NAD kinase by DEAEceilulose column chromatography resulted in loss of activity, due to dissociation of an activator from the enzyme. The purified enzyme preparation, which was almost completely inactive, regained the activity when the activator was added back.The activator was purified 320-fold by ion exchange chromatographies. The (23,24) reported that red light stimulated the conversion of NAD to NADP, and suggested that the NAD kinase activity was controlled by phytochrome.To elucidate the controlling mechanism of the NAD kinase activity in vivo, it is important to study the properties of the enzyme using a highly purified preparation. The most highly purified enzyme from plant has been obtained by Yamamoto (26). While trying to improve further the purity of plant NAD kinase, we found an activator of this enzyme. This communication describes some properties of the partially purified activator from pea seedlings, as well as the distribution of the activator in various green plants and Chlorella cells. ' This research was supported by a grant from the Japanese Ministry of Education. MATERIALS AND METHODSPlant Materials. Unless otherwise mentioned, the experiments were carried out with pea seedlings. Seeds of pea (Pisum sativum cultivar Gokuwase-akabana-tenashi-endo) were germinated in trays filled with vermiculite. The trays were placed in a greenhouse and irrigated once a day. The temperatures during daytime and the rest of the day were kept at 25 and 20 C, respectively. Seedlings grown under natural light conditions for 12 days were used for the experiments.To examine the distribution of NAD kinase and its activator among various plants, the respective seedlings of corn (Zea mays, cultivar, Nagano No. 1), and rice (Oriza sativa, cultivar Nihon-bare) grown in the greenhouse for 2 and 3 weeks were used. Chlorella vulgaris 11 hr cells were grown autotrophically with constant bubbling of air containing about 2% CO2 (15). Spinach (Spinacia oleracea L.) and Chinese cabbage (Brassica rapa var. Previdis) were purchased from the local market.Assay of NAD Kinase. The method adopted was essentially the same as described by Wang and Kaplan (25). The routine incubation medium contained 2 mm NAD, 3 mm ATP, 10 mM MgCI2, 100 mm tris-HCI (pH 8), an appropriate amount of enzyme, and 10 units (see below) of the activator where necessary, in a final volume of 0.5 ml. The reaction was initiated by adding NAD and terminated with 100 ,ul of N HCI. The reaction was run for 30 min at 37 C. The acidified suspension was neutralized with 100 Al of N NaOH and the coagulated protein was removed by centrifugation. The clear supernatant thus obtained was subjected to the determination of NADP according to the method described by Apps (2).The assay system of NADP cgntained 0.25 M tris-HCI (pH 8), 30 Ag of 2,6-dichlorophenol indophenol, 20 ,ug of phenazine methosulfate, 0.2 mm glucose-6-P, 0.06 unit of glucose-6-P dehydrogenase, and an appropriate amount of the supernatant (NADP), in a...

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“…Because pancreatic lipase is usually unsaturated with respect to cofactor, lipolytic activity in duodenal secretions may be finely controlled by modulation of colipase secretion. INTRODUCTION Pancreatic lipase in its pure form is inactive in the presence of the supramicellar bile salt concentrations characteristic of human duodenal secretions (1)(2)(3), but, in life, inactivation is prevented by cosecretion of the pancreatic protein cofactor colipase. Colipases have been isolated and purified from several species (4-7), including man (8), and appear to be quite similar, each having a molecular weight of -10,000, with 100±10 amino acid residues, five disulfide bridges, and little or no carbohydrate (9).…”

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confidence: 99%