Experimental and Theoretical Bases of Specific Affinity, a Cytoarchitecture-Based Formulation of Nutrient Collection Proposed To Supercede the Michaelis-Menten Paradigm of Microbial Kinetics

A theory for solute uptake by whole cells was derived with a focus on the ability of oligobacteria to sequester nutrients. It provided a general relationship that was used to obtain the kinetic constants for in situ marine populations in the presence of naturally occurring substrates. In situ affinities of 0.9 to 400 liters g of cells⁻¹ h⁻¹ found were up to 10³ times smaller than those from a “Marinobacter arcticus ” isolate, but springtime values were greatly increased by warming. Affinities of the isolate for usual polar substrates but not for hydrocarbons were diminished by ionophores. A kinetic curve or Monod plot was constructed from the best available data for cytoarchitectural components of the isolate by using the theory together with concepts and calculations from first principles. The order of effect of these components on specific affinity was membrane potential > cytoplasmic enzyme concentration > cytoplasmic enzyme affinity > permease concentration > area of the permease site > translation coefficient > porin concentration. Component balance was influential as well; a small increase in cytoplasmic enzyme concentration gave a large increase in the effect of permease concentration. The effect of permease concentration on specific affinity was large, while the effect on K_m was small. These results are in contrast to the Michaelis-Menten theory as applied by Monod that has uptake kinetics dependent on the quality of the permease molecules, with K_m as an independent measure of affinity. Calculations demonstrated that most oligobacteria in the environment must use multiple substrates simultaneously to attain sufficient energy and material for growth, a requirement consistent with communities largely comprising few species.     

RATE OF RESPIRATION AS RELATED TO AGE

In the present paper it is shown that as the leaves of corn, sorghum, wheat, and oats increase in age there is a decrease in rate of respiration; but that as the leaves become still older (past about middle age) the rate gradually increases.     

Antibodies that recognize phosphodiester-linked amino-N-acetylglucosamine-1-phosphate residues

An affinity chromatography procedure was developed for isolating antibodies that recognized phosphodiester-linked alpha-N-acetylglucosamine-1-phosphate (alpha-GlcNAc-1-P) residues. The affinity resin consisted of uridine-5'-diphospho-alpha-N-acetylglucosamine (UDPGlcNAc) conjugated to Sepharose. Antiserum prepared against Proteinase 1 from the cellular slime mold, Dictyostelium discoideum was used as a source of the anti-alpha-GlcNAc-1-P antibodies. Immunoblot assays showed that the affinity-isolated antibodies recognized phosphoglycosylated subunits of Proteinase 1, and that UDPGlcNAc blocked this interaction.     

A Method for Identification and Analysis of Non-Overlapping Myeloid Immunophenotypes in Humans

The development of flow cytometric biomarkers in human studies and clinical trials has been slowed by inconsistent sample processing, use of cell surface markers, and reporting of immunophenotypes. Additionally, the function(s) of distinct cell types as biomarkers cannot be accurately defined without the proper identification of homogeneous populations. As such, we developed a method for the identification and analysis of human leukocyte populations by the use of eight 10-color flow cytometric protocols in combination with novel software analyses. This method utilizes un-manipulated biological sample preparation that allows for the direct quantitation of leukocytes and non-overlapping immunophenotypes. We specifically designed myeloid protocols that enable us to define distinct phenotypes that include mature monocytes, granulocytes, circulating dendritic cells, immature myeloid cells, and myeloid derived suppressor cells (MDSCs). We also identified CD123 as an additional distinguishing marker for the phenotypic characterization of immature LIN^-CD33⁺HLA-DR^- MDSCs. Our approach permits the comprehensive analysis of all peripheral blood leukocytes and yields data that is highly amenable for standardization across inter-laboratory comparisons for human studies.     

Evidence for phosphoryl moieties in a proteinase from Dictyostelium discoideum.

A proteinase (called Proteinase I) present in myxamoebae of the cellular slime mold, $\text{Dictyostelium}\text{discoideum}$, was labeled $\text{in}\text{vivo}$ with [³²P] by growth of cells on media containing [³²P] orthophosphate. The labeled proteinase was purified to apparent homogeneity and characterized by dissociation chromatography and quantitative immune-precipitin analysis. Based upon the results of these studies it was concluded that phosphoryl moieties were tightly associated (presumably covalently bonded) with the polypeptide subunits of Proteinase I.     

Ferric iron reduction by sulfur- and iron-oxidizing bacteria.

Acidophilic bacteria of the genera Thiobacillus and Sulfolobus are able to reduce ferric iron when growing on elemental sulfur as an energy source. It has been previously thought that ferric iron serves as a nonbiological oxidant in the formation of acid mine drainage and in the leaching of ores, but these results suggest that bacterial catalysis may play a significant role in the reactivity of ferric iron.