Purification and molecular characterization of bovine pregastric lipase

Bernbäck, Stefan; Hernell, Olle; Bläckberg, Lars

doi:10.1111/j.1432-1033.1985.tb08830.x

Cited by 49 publications

(9 citation statements)

References 29 publications

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“…Gastric and lingual lipases, which are analogous in both structure and function (53)(54)(55)(56)(57), are reported to exhibit considerable stereospecificity for the a-position of the TG and to hydrolyze the an-3 position twice as fast as the an-1 position (23, [58][59][60][61]. In this study, the primary products of hydrolysis were afl-DG and FFA in all three seal species.…”

Section: Gastric Hydrolysis Of Seal Milk Triglyceridesmentioning

confidence: 75%

Positional specificity of gastric hydrolysis of long‐chain n−3 polyunsaturated fatty acids of seal milk triglycerides

Iverson

Sampugna

Oftedal

1992

Lipids

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Long-chain n-3 polyunsaturated fatty acids (n-3 PUFA) of marine oils are important dietary components for both infants and adults, and are incorporated into mlUo~ following maternal dietary intake. However, little is known about the hydrolysis of these PUFA from milk triglycerides (TG) by lipases in suckling young. Seals, like human~, possess gastric lipase; however, the milk lipids of seals and sea lions are almost devoid of the readily hydrolyzable medium,chain fatty acids, and are characterized by a large percentage (10-30%) of n-3 PUFA. Gastric hydrolysis of milk lipids was studied in vivo in suckling pups of three species (the California sea lion, the harp seal and the hooded seal) in order to elucidate the actions and specifit~ ity of gastric lipases on milk TG in relation to fatty acid composition and TG structure. Regardless of milk fat content (31-61% fat) or extent of gastric hydrolysis (10-56%), the same fatty acids were preferentially released in all three species, as determined by their relative enrichment in the free fatty acid (FFA) fraction. In addition to 16:1 and 18:0, these were the PUFA of 18 carbons and longer, except for 22:6n-3. Levels of 20:5n-3 were most notably enriched in FFA, at up to five times that found in the TG. Although 22:6n-3 was apparently also released from the TG (reduced in the diglyceride), it was also notably re~ duced in FFA. Positional analysis of milk TG based on the products of Grignard hydrolysis revealed that these PUFA, including 22:6n-3, were preferentially esterified at the a-position of the TG, and that the fatty acids not released during gastric hydrolysis were located at the sn-2 position. The extreme reduction of 22:6n~ and enrichment of 20:5n-3 in FFA is discussed. Results from this study are consistent with reports that gastric lipase acts stere~ specifically to release fatty acids at the a-positions (sn-3, sn-1). We conclude that the n-3 PUFA in milk are efficiently hydrolyzed by gastric lipase and that this has important implications for digestion of milks enriched in PUFA by neonates in general. Lipids 27, 870-878 (1992).Long-chain n-3 polyunsaturated fatty acids (n-3 PUFA), characteristic of marine otis, have become a major focus of research due to their potent

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Section: Gastric Hydrolysis Of Seal Milk Triglyceridesmentioning

confidence: 75%

Positional specificity of gastric hydrolysis of long‐chain n−3 polyunsaturated fatty acids of seal milk triglycerides

Iverson

Sampugna

Oftedal

1992

Lipids

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“…Most previous studies on pregastric lipases have been carried out with crude enzyme preparations and there exist only few kinetic and biochemical data on the purified enzymes [11–13]. In this paper, we report the results of the purification and partial characterization of the lipase from Cephaloleia presignis .…”

Section: Introductionmentioning

confidence: 99%

Purification and properties of a lipase from Cephaloleia presignis (Coleoptera, Chrysomelidae)

Arreguı́n-Espinosa¹,

Arreguı́n²,

González³

2000

Biotech and App Biochem

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A novel lipase from the insect Cephaloleia presignis was purified by a procedure involving ammonium sulphate precipitation, and Phenyl Toyopearl 650M, DEAE-5PW and hydrophobic-interaction column chromatographies. The purified lipase was homogeneous with a molecular mass of 31000 Da by SDS/PAGE and of 29000 Da by gel filtration on a Superose 12 column. The enzyme was identified as a glycoprotein with a pI of 6.9. The enzyme unspecifically liberated short-chain to long-chain fatty acids from p-nitrophenyl esters, methyl esters and triglycerides. The N-terminal 28 amino acid residues were determined as AGTLGYATRHVLPIFTLDDYTGSNEMWG, which showed no similarity with known proteins, suggesting that the purified lipase may belong to a novel class of hydrolases.

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“…The final preparation gave a single band of 50 kDa on SDS\PAGE and an overall recovery of 14 %. Two previously published purification procedures [15,16] reported a similar molecular mass and resulted in a yield of 15 % and 26 % respectively. Neither of these two methods gave a satisfactory result in our laboratory.…”

Section: Discussionmentioning

confidence: 81%

“…In the present study, a purification method for PGE, different from previously published methods [15,16], is described. Also the effects of serine-and cysteine-specific reagents on PGE activity are investigated.…”

Section: Introductionmentioning

confidence: 99%

Inhibition studies on calf pregastric esterase: the enzyme has no functional thiol group

Timmermans

Reekmans

Teuchy

et al. 1996

Biochemical Journal

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Pregastric esterase (PGE) (EC 3.1.1.3) was purified to homogeneity from calf pharyngeal tissue. The enzyme had an apparent molecular mass of 50 kDa, as determined by SDS/PAGE. The serine-binding reagent diethyl p-nitrophenyl phosphate was a potent inhibitor of PGE. This is in accordance with the claim that a functional serine residue is necessary for the lipolytic activity of lipases. PGE was not inhibited by the thiol reagents 5,5'-dithiobis(2-nitrobenzoic acid) or 4,4'-dithiopyridine. A partial inhibition with dodecyldithio-5-(2-nitrobenzoic acid) was observed, but the same degree of inhibition was caused by the non-esterified fatty acid C(12:0). PGE shows a great sequence similarity to gastric lipases. Gastric lipases have three cysteine residues, and two of these form a disulphide bridge. Blocking the remaining free cysteine with thiol reagents inactivates the gastric lipases. The fact that PGE is not inhibited by thiol reagents indicates that PGE has no functional free thiol group. The PGE cDNA codes only for two cysteines, and their involvement in the formation of a disulphide bridge was demonstrated.

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Purification and molecular characterization of bovine pregastric lipase

Cited by 49 publications

References 29 publications

Positional specificity of gastric hydrolysis of long‐chain n−3 polyunsaturated fatty acids of seal milk triglycerides

Positional specificity of gastric hydrolysis of long‐chain n−3 polyunsaturated fatty acids of seal milk triglycerides

Purification and properties of a lipase from Cephaloleia presignis (Coleoptera, Chrysomelidae)

Inhibition studies on calf pregastric esterase: the enzyme has no functional thiol group

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