Experiments in which [1-(14)C]glycolate uptake is carried out in conjunction with measurements of stromal pH indicate that only glycolic acid and not the glycolate anion is crossing the pea (Pisum sativum var. Progress No. 9, Agway) chloroplast envelope. This mechanism of glycolate transport appears to be too slow to account for observed photorespiratory carbon fluxes in C(3) plants.

The TBDPS protected glycolate derivative of thiol auxiliary 1 is readily prepared (3 steps, 80% overall yield) and has been shown to give excellent anti:syn selectivity (>97:3) and high facial selectivity (88:12 to 97:3) in glycolate aldol reactions with a range of aldehydes (75-87% isolated yield major diastereomer). In contrast, its benzyl protected counterpart displays more versatility with ...

The glycolate/glycerate transporter of spinach (Spinacia oleracea L.) chloroplast inner envelope membranes was solubilized by treatment of the membranes with sodium cholate. Mixtures of the cholate extracts and soy asolectin were subjected to gel filtration to remove the detergent. The reconstituted vesicles were frozen, thawed, and sonicated in a buffer that contained 10 millimolar d-glycerate...

There are two independent formula units in the asymmetric unit of the title compound, C(4)H(10)NO(+)·C(6)H(2)N(3)O(7) (-). The morpholinium cations in both mol-ecules are puckered and adopt a chair conformation. Intermolecular N-H⋯O and C-H⋯O inter-actions generate rings of motifs R(2) (1)(5) and R(1) (2)(6). The supra-molecular aggregation is completed by the presence of two co-operative hydro...

Photosynthesis by Synechococcus lividus, the sole oxygenic phototroph inhabiting the surface of the 55 degrees C cyanobacterial mat in Mushroom Spring, Yellowstone National Park, causes superoxic and alkaline conditions which promote glycolate photoexcretion. At O(2) concentrations characteristic of the top 2 mm of mat during the day, up to 11.8% of NaHCO(3) fixed in the light was excreted, and...

The flow of glyoxylate derived from glycolate into various metabolic routes in the peroxisomes during photorespiration was assessed. Isolated spinach leaf peroxisomes were fed [(14)C] glycolate in the absence or presence of exogenous glutamate, and the formation of radioactive glyoxylate, CO(2), glycine, oxalate, and formate was monitored at time intervals. In the absence of glutamate, 80% of t...

Photorespiration is an energy-intensive process that recycles 2-phosphoglycolate, a toxic product of the Rubisco oxygenation reaction. The photorespiratory pathway is highly compartmentalized, involving the chloroplast, peroxisome, cytosol, and mitochondria. Though the soluble enzymes involved in photorespiration are well characterized, very few membrane transporters involved in photorespiratio...

The enzymic oxidation of glycolate to glyoxylate and glyoxylate to oxalate by preparations purified from tobacco (Nicotiana tabacum var Havana Seed) leaves was studied. The K(m) values for glycolate and glyoxylate were 0.26 and 1.0 millimolar, respectively. The ratio of glycolate to glyoxylate oxidation was 3 to 4 in crude extracts but decreased to 1.2 to 1.5 on purification by (NH(4))(2)SO(4) ...

The utilization of nitrate and ammonia as nitrogen sources had different effects on the metabolism of glycolate in Cholorella sorokiniana. During photolithotrophic growth with nitrate as nitrogen source, glycolate was metabolized via the glycine-serine pathway. Ammonia, produced as a result of glycolate metabolism, was reassimilated by glutamine synthetase. Two isoforms of this enzyme were pres...

In the title mol-ecular salt, C(4)H(10)NO(+)·C(4)H(5)O(6) (-), the morpholinium cation adopts a chair conformation. The conformation of the C-C-C-C backbone of the monotartrate anion is close to anti [torsion angle = 173.18 (17)°], which is supported by two intra-molecular O-H⋯O hydrogen bonds. In the crystal, the components are linked by N-H-O and O-H-O hydrogen bonds, generating (001) sheets.