Format

Send to

Choose Destination
J Biosci. 2008 Dec;33(5):771-80.

Branch-point stoichiometry can generate weak links in metabolism: the case of glycine biosynthesis.

Author information

1
Instituto del Metabolismo Celular,Carretera Vecinal de El Sauzal, n 160 A,,El Sauzal, 38360 Tenerife, Canary Islands, Spain. emelhevia@metabolismo.ws

Abstract

Although the metabolic network permits conversion between almost any pair of metabolites,this versatility fails at certain sites because of chemical constraints (kinetic,thermodynamic and stoichiometric) that seriously restrict particular conversions. We call these sites weak links in metabolism,as they can interfere harmfully with management of matter and energy if the network as a whole does not include adequate safeguards. A critical weak link is created in glycine biosynthesis by the stoichiometry of the reaction catalyzed by glycine hydroxymethyltransferase (EC 2.1.2.1), which converts serine into glycine plus one C1 unit: this produces an absolute dependence of the glycine production flux on the utilization of C1 units for other metabolic pathways that do not work coordinately with glycine use. It may not be possible,therefore,to ensure that glycine is always synthesized in sufficient quantities to meet optimal metabolic requirements.

PMID:
19179765
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Indian Academy of Sciences
Loading ...
Support Center