Amino acid catabolism in the nematodes Heligmosomoides polygyrus and Panagrellus redivivus 2. Metabolism of the carbon skeleton

SUMMARYAll of the enzymes of proline catabolism were present in Heligmosomoides polygyrus and Panagrellus redivivus and the activities were, in general, similar to those found in rat liver. Both nematodes were also shown to be able to catabolize the branched-chain amino acids leucine, isoleucine and valine, by pathways similar to those found in mammalian liver. There were no significant differences in amino acid catabolism between the animal-parasitic and free-living species of nematode.

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Expression in Lactococcus lactis of functional genes related to amino acid catabolism and cheese aroma formation is influenced by branched chain amino acids

International Journal of Food Microbiology ◽

10.1016/j.ijfoodmicro.2012.09.002 ◽

2012 ◽

Vol 159 (3) ◽

pp. 207-213 ◽

Cited By ~ 12

Author(s):

Tomás García-Cayuela ◽

Luz P. Gómez de Cadiñanos ◽

Carmen Peláez ◽

Teresa Requena

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Lactococcus Lactis ◽

Branched Chain Amino Acids ◽

Functional Genes ◽

Amino Acid Catabolism ◽

Cheese Aroma ◽

Branched Chain

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Amino acid catabolism by perfused rat hindquarter. The metabolic fates of valine

Biochemical Journal ◽

10.1042/bj2330621 ◽

1986 ◽

Vol 233 (3) ◽

pp. 621-630 ◽

Cited By ~ 31

Author(s):

S H C Lee ◽

E J Davis

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Degradation Products ◽

Plasma Concentrations ◽

Branched Chain Amino Acids ◽

Total Amino Acid ◽

Amino Acid Catabolism ◽

Citrate Cycle ◽

Important Intermediate ◽

Branched Chain

Hindquarters from starved rats were perfused with plasma concentrations of amino acids, but without other added substrates. Release of amino acids was similar to that previously reported, but, if total amino acid changes were recorded, alanine and glutamine were not formed in excess of their occurrence in muscle proteins. In protein balance (excess insulin) there was no net formation of either alanine or glutamine, even though the branched-chain amino acids and methionine were consumed. If [U-14C]valine was present, radiolabelled 3-hydroxyisobutyrate and, to a lesser extent, 2-oxo-3-methylbutyrate accumulated and radiolabel was incorporated into citrate-cycle intermediates and metabolites closely associated with the citrate cycle (glutamine and glutamate, and, to a smaller extent, lactate and alanine). If a 2-chloro-4-methylvalerate was present to stimulate the branched-chain oxo acid dehydrogenase, flux through this step was accelerated, resulting in increased accumulation of 3-hydroxyisobutyrate, decreased accumulation of 2-oxo-3-methylbutyrate, and markedly increased incorporation of radiolabel (specific and total) into all measured metabolites formed after 3-hydroxyisobutyrate. It is concluded that: amino acid catabolism by skeletal muscle is confined to degradation of the branched-chain amino acids, methionine and those that are interconvertible with the citrate cycle; amino acid catabolism is relatively minor in supplying carbon for net synthesis of alanine and glutamine; and partial degradation products of the branched-chain amino acids are quantitatively significant substrates released from muscle for hepatic gluconeogenesis. For valine, 3-hydroxyisobutyrate appears to be quantitatively the most important intermediate released from muscle. A side path for inter-organ disposition of the branched-chain amino acids is proposed.

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