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G L Moore

Publications and source records attributed to G L Moore.

At least 55 records · Page 3Linked to original sources
PubMed1968

Protein conformation in solution: cross-linking of lysozyme.

The cross-linking of lysozyme by reaction with phenol-2,4-disulfonyl chloride has been effected. The cross-linked protein retained enzymatic activity, has approximately the same molecular weight as native lysozyme, and has essentially the same conformation as native lysozyme as judged by optical rotatory dispersion analysis. The positions of sulfonylation were assigned by a standard degradation sequence; the presence of sulfonamide bonds was confirmed by infrared spectroscopy. Cross-links may thus be introduced without incurring major structural changes in the protein, and certain intramolecular distances that are allowed in the active enzyme may be deduced.

Amino Acids↗
PubMedDate not supplied

Reexamination of the polymerization of pyridoxylated hemoglobin with glutaraldehyde.

Pyridoxylated adult human hemoglobin (HbAo) was prepared using a one molar equivalent of pyridoxal 5-phosphate (PLP) per heme and reduced with either NaCNBH3 or NaBH4. A separate sample was pyridoxylated and passed through a mixed-bed ion exchange column without reduction. All three preparations had a P50 of 29 +/- 2 torr and a cooperativity of n = 2.4 +/- 0.1. These preparations, in both the oxy and deoxy forms, were then treated with 7 equivalents of glutaraldehyde per tetramer at pH 6.8 at 4 degrees C and at room temperature. The polymerization invariably reduced the P50 to 18 +/- 2 torr with Hill coefficients of less than 2. These solutions, with or without further reduction using NaCNBH3, all retained the PLP in differing amounts (2-3 moles/tetramer). Methemoglobin concentrations were increased during the polymerization reaction. The normal pyridoxylation procedure, using sodium borohydride reduction, resulted in a number of different molecular species. Polymerization with glutaraldehyde caused a further proliferation of molecular species that could not be separated by anion exchange chromatography or by isoelectric focusing. The extent of polymerization, estimated by gel exclusion chromatography and SDS polyacrylamide gel electrophoresis, was from 40 to 50%. Analysis of the reverse phase chromatograms, which separate the heme and the alpha- and beta-chains, showed extensive polymerization and distribution of the radioactively labeled PLP on the protein for all preparations. All of the polymerized and pyridoxylated samples were unstable, and showed different chromatographic patterns after storage at 4 degrees C for 1 month. Attempts to stabilize these preparations by further reduction with NaCNBH3 gave products with a lower P50 and lower cooperativity. When the reactions were conducted with a purified HbAo, heterogeneity was somewhat decreased compared to the normally used stroma-free hemoglobin, but a large number of molecular species were still formed.

Aldehydes↗
PubMedDate not supplied

The renal effect of intravenous adenine in humans.

The purine base, adenine, improves the posttransfusion viability of liquid stored blood. However, adenine in high doses may cause kidney damage becuase of the precipitation in renal tubules of its incoluble metabolite, 2,8-dioxyadenine. Adenine is not licensed for use in the United States because it may be nephrotoxic. In a controlled, randomized, double-blind study, eight human subjects received 10 mg/kg of adenine infused intravenously over one hour, four subjects received 5 mg/kg, and four subjects received no adenine. Renal function tests were performed on each subject before adenine infusion and one day and one week following the infusion. Tests included an assessment of glomerular function (serum creatinine, creatinine clearance, protein excretion), proximal tubular function (amino acid and glucose excretion), and distal tubular function (maximal acidifying and concentrating ability). Plasma and urine levels of adenine and 2,8-dioxyadenine were measured. Renal function tests showed no evidence of kidney damage secondary to adenine.

Adenine↗
PubMedDate not supplied

The uptake and egress of adenine from human red blood cells in vitro.

The initial uptake of adenine from plasma by human red blood cells was measured at 0, 10, and 20 C. Initial uptake is completed in several minutes as distribution equilibrium is reached; however, total uptake requires several weeks at 4 C. Adenine inside the red blood cell was shown to egress to the plasma if the equilibrium shifted due to plasma dilution or exchange.

Adenine↗
PubMedDate not supplied

Enhanced solubility of 2,8 dihydroxyadenine (DOA) in human urine.

Water solubility of the adenine catabolite 2,8 dihydroxyadenine (DOA) frequently forms the basis for predicting potential DOA crystal formation in human urine following infusion of adenine-fortified blood. Measurements relevant to solubility, ionic dissociation, and supersaturability of DOA in aqueous buffers and human urine at 37 C establish striking quantitative differences in the physico-chemical behavior of DOA in the two media. The basal solubility of DOA is 1.53 +/- 0.04 mg/1 (approximately 9 X 10(-6) M) in water (pH 6.5). DOA is an ampholyte characterized by aqueous thermodynamic macrodissociation constants of pKa1 = 2.6, pKa2 = 8.1, and pKa3 = 11.52. This compound displays pH-dependent solubility, although significant solubility increases beyond basal values do not occur within the physiologic pH range for human urine. Supersaturated aqueous solutions (three to sixteen times basal solubility) can be achieved but are unstable. In contrast, human urine at 37 C exhibits enhanced capacity for solubilizing DOA. In vitro basal solubility is 2.68 +/- 0.84 mg/1 at pH 5.0 and 4.97 +/- 1.49 mg/1 at pH 7.8. The apparent pK 2for DOA in urine of 7.9 to 8.1 is dependent upon urine osmolality. Urine can be supersaturated with Doa in vitro to approximately ten times its basal solubility by adding DOA solubilized in weak base, or by evaporation of a urine-DOA mixture. DOA remains supersaturated in urine for at least 16 hours despite gentle agitation. Little variation in in vitro DOA apparent supersaturation was found among urine samples from four normal individuals (40.38 +/- 3.33 mg/1). A patient receiving oral adenine exhibited urinary DOA solubility in considerable excess (96.0 mg/1) of that predicted from water and from in vitro urine solubility studies. Thus, water solubility of DOA is poorly predictive of in vitro and in vivo DOA solubility in human urine. On the basis of these data, estimates of the load of adenine-fortified blood expected to result in urinary DOA crystal formation may be revised upward.

Adenine↗
PubMedDate not supplied

Plasma adenine and cellular ATP in red cell concentrates collected and stored in modified CPD at 4 C.

Eight units of blood were drawn into modified CPD containing 25 per cent higher glucose and 17.3 mg adenine (0.25 mM in blood). Red blood cell concentrates (RCC) were prepared to a mean hematocrit (Hct) of 70, the cells stored at 4 C, and plasma adenine and red blood cell adenosine triphosphate (ATP) were measured weekly for 42 days. The removal of plasma in the preparation of RCC reduced by 39 per cent the available adenine. As a result measurable plasma adenine was depleted by 21 days. The loss of ATP in RCC occurs at a significantly faster rate than in whole blood stored under the same conditions. When red blood cells are stored at higher HCT or for periods longer than 35 days, increased anticoagulant adenine levels are recommended.

Adenine↗
PubMedDate not supplied

The potential use of dihydroxyacetone for improved 2,3-DPG maintenance in red blood cell storage: solution stability and use in packed cell storage.

Dihydroxyacetone (DHA) is effective in maintaining 2,3-diphosphoglycerate (2,3-DPG) concentrations in stored red blood cells. One limitation to the use of DHA is its instability when added to anticoagulant solutions during blood bag manufacture. The stability of DHA solutions have been evaluated. Solutions of DHA are stable at 25 C in water or isotonic saline, with or without the addition of glucose or adenine. DHA is stable to autoclaving; 99 + per cent surviving at 150 mM, and 89 per cent surviving at 1.9 M concentrations. DHA can be incorporated into a satellite addition pouch attached to the main blood drawing bag, and be added to the blood-anticoagulant mixture after phlebotomy or the preparation of red blood cells. Addition of the DHA solution, containing adenine and extra glucose, to packed cells causes significantly improved maintenance of 2,3-DPG during 42 days of 4 C storage, while maintaining adequate concentrations of red blood cell ATP. The use of DHA, adenine, and glucose in extended storage of packed cells, using either zero or seven day addition of the nutrient solution, produces similar efficacious results.

Adenosine Triphosphate↗
PubMedDate not supplied

The in vitro evaluation of modifications in CPD-adenine anticoagulated-preserved blood at various hematocrits.

Erythrocytes stored in the new CPD-adenine anticoagulant (CPDA-1) barely met the 70 per cent 24-hour postinfusion 51Cr recoveries on day 35 when stored at hematocrit greater than or equal to 75 per cent. CPDA-1 differs from CPD in that it has 1.25 times the glucose concentration plus 17.3 mg adenine/63 ml. In an effort to improve the survivability (or viability) of red blood cells following extended storage (35+ days), two new CPD-adenine anticoagulants have been tested in vitro. CPDA-2 and CPDA-3 (both of which contain 34.6 mg/63 ml of anticoagulant or 0.50 mM adenine [final blood concentration], and either 1.75 times or 2.0 times respectively the amount of glucose used in CPD) have been tested for whole blood or red blood cell storage to 42 days. Red blood cell ATP concentrations were better maintained throughout 42 days of storage in both of these formulations than in CPDA-1 at hematocrits that ranged from 40 to 85. Other biochemical parameters (2,3-DPG, pH, plasma hemoglobin) were similar to those of blood stored in CPD or CPDA-1.

Adenine↗