Influence of altered blood oxygen affinity on maximal performance ability was evaluated in trained rats exercising to exhaustion in a graded treadmill test. Modification of blood oxygen affinity was achieved both by 2,3-diphosphoglycerate depletion, accomplished by exposure of animals to CO(2) and by exchange transfusion with blood exposed to bisulfite or stored in acid citrate dextrose, and by...

The structure of the unactivated form of ribulose-1,5-bisphosphate carboxylase/oxygenase was refined at a resolution of 2.0 A to an R-factor of 17.1%. The previous model (Chapman et al., 1988) was extensively rebuilt, and the small subunit was retraced. The refined model consists of residues 22-63 and 69-467 of the large subunit and the complete small subunit. A striking feature of the model is...

A chromatographic method for determining glycated hemoglobin (Hb A1c) by use of a new monodisperse cation-exchanger has been investigated. Hb A1c was separated from other "minor hemoglobins": Hb F, Hb A3 (the glutathione adduct), and the acetaldehyde adduct in alcoholics. The method was fully automated and a single column could be used for more than 1000 runs. The normal reference interval was ...

Urease is a metalloenzyme essential for the survival of Helicobacter pylori in acidic gastric environment. Maturation of urease involves carbamylation of Lys219 and insertion of two nickel ions at its active site. This process requires GTP hydrolysis and the formation of a preactivation complex consisting of apo-urease and urease accessory proteins UreF, UreH, and UreG. UreF and UreH form a com...

How lipid transmitters move within and between cells to communicate signals remains an important and largely unanswered question. Integral membrane transporters, soluble lipid-binding proteins, and metabolic enzymes have all been proposed to collaboratively regulate lipid signaling dynamics in vivo. Assignment of the relative contributions made by each of these classes of proteins requires sele...

Controlled inhibition of brain acetyl- and butyrylcholinesterases (AChE and BChE, respectively) and of monoamine oxidase-B (MAO-B) may slow neurodegeneration in Alzheimer's and Parkinson's diseases. It was postulated that certain carbamate esters would inhibit AChE and BChE with the concomitant release in the brain of the OH-derivatives of rasagiline or selegiline that can serve as inhibitors o...

A cDNA clone for the stress-inducible 70 kDa heat-shock protein (Hsp70) has been isolated from a bovine skeletal-muscle cDNA library. This mRNA encodes a protein with a calculated molecular mass of 70250 Da. The cDNA has one continuous open reading frame capable of encoding a 641-amino-acid protein. Expression of this cDNA in a bacterial expression system produced a protein with a mobility iden...

Mitochondrial dysfunction is often observed in aging skeletal muscle and is implicated in age-related declines in physical function. Early evidence suggests that dietary omega-3 polyunsaturated fatty acids (n-3 PUFAs) improve mitochondrial function. Here, we show that 10 weeks of dietary eicosapentaenoic acid (EPA) supplementation partially attenuated the age-related decline in mitochondrial fu...

We previously showed that immunization of guinea pigs with reductively glucosylated guinea pig low density lipoprotein (LDL) or albumin resulted in the formation of antibodies specific for the glucosylated protein. The present studies were done to determine if modifications of homologous LDL or albumin, other than addition of carbohydrate, would also render these proteins immunogenic. We found ...

Cyanate inhibits hemoglobin synthesis in vitro. In vivo studies were performed to determine the effect of the drug on erythropoiesis. Adult female rats received daily intraperitoneal injections of 400 /.Lmoles of cyanate, leading to over 3 CNO/Hb by 3 wk. Controls received sodium chloride. DPG was measured in a small number of animals and declined from 5.5 to 4.1 mmoles/liter (p <0.02). At 4 wk...