Some physico-chemical properties of mouse red cells and hemoglobin

Zusammenfassung Hämoglobin und Erythrozyten von prä- und postnatal untersuchten Inzuchtmäusen verhalten sich, was verschiedene physikalisch-chemische Analysen betrifft, ähnlich. Die Existenz eines fötalen Hämoglobins konnte nicht bewiesen werden.

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This investigation was supported by a grant from the National Institutes of Health, P.H.S. C-4691.     

Immunological properties of oxygen-transport proteins: hemoglobin,hemocyanin and hemerythrin

It is now well documented that peptides with enhanced or alternative functionality (termed cryptides) can be liberated from larger, and sometimes inactive, proteins. A primary example of this phenomenon is the oxygen-transport protein hemoglobin. Aside from respiration, hemoglobin and hemoglobin-derived peptides have been associated with immune modulation, hematopoiesis, signal transduction and microbicidal activities in metazoans. Likewise, the functional equivalents to hemoglobin in invertebrates, namely hemocyanin and hemerythrin, act as potent immune effectors under certain physiological conditions. The purpose of this review is to evaluate the true extent of oxygen-transport protein dynamics in innate immunity, and to impress upon the reader the multi-functionality of these ancient proteins on the basis of their structures. In this context, erythrocyte–pathogen antibiosis and the immune competences of various erythroid cells are compared across diverse taxa.     

Hydroxyapatite: Preparation and properties

Zusammenfassung Es wurden sowohl ältere als auch neuere Verfahren zur Fällung von Kalziumhydroxyapatit aus wässriger Lösung vergleichend überprüft und die erhaltenen Präparate mittels chemischer und physikalischer Methoden charakterisiert, wobei sich ergab, dass das vom National Bureau of Standards entwickelte Verfahren die am besten definierten Kristalle liefert.

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Acknowledgment. The authors are indebted to the late Dr.R. V. Coates for the X-ray diffraction analyses and to Mr.R. D. Woods, Department of Plant Pathology, Rothamsted Experimental Station for the electron micrographs.     

Preparation and properties of hexitol-lysyl conjugates

Summary The facile preparation of hexitol-lysyl derivatives is reported. Some of the properties of these compounds, particularly those relevant to protein structural studies, are described.Supported by grants from Medical Research Council of New Zealand, New Zealand Neurological Foundation and National Heart Foundation of New Zealand.     

Hybrid formation in mixtures of globins from different species

Riassunto Miscele di globine preparate da emoglobina umana e canina, tenute a pH neutro e a 4C, mostrano dopo alcuni giorni la formazione di molecole ibride. Nelle stesse condizioni miscele di emoglobine non presentano una formazione significativa di ibridi. I risultati indicano ehe i legami sono più forti nell'emoglobina che nella globina.     

Comparison of human adult and fetal hemoglobin: Aminophenol-induced methemoglobin formation

Summary Human fetal hemoglobin was more susceptible to methemoglobin formation in the presence of aminophenols than was adult hemoglobin. This was due to the intrinsic properties of the proteins rather than the presence of methemoglobin reductases.This work was supported by a grant from the National Institute of General Medical Sciences GM-17184.     

Desacetyl-rifamycins: Preparation and antibacterial properties

Riassunto Vengono descritte la sintesi, le proprietà chimico-fisiche e l'attività antibatterica in vitro di alcune desacetil-rifamicine. Vengono discusse le variazioni osservate nello spettro antibatterico in confronto con gli analoghi acetilati al C-25.

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Rifamycins LV [Rifamycins LIV:S. Füresz, R. Scotti, R. Pallanza andE. Mapelli, Arzneimittel-Forsch.17, 726 (1967)].     

Preparation and properties of a soluble trypsin-dextran conjugate

Zusammenfassung Durch kovalente Bindung an Polyaldehyd-dextran wird Trypsin immobilisiert. Die polymerische Matrix stabilisiert das Enzym und bewirkt eine pH-Erhöhung der maximalen Aktivität, beeinflusst aber den Michaelis-Menten Parameter für die Hydrolyse des Substrates BAPNA nicht.

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The author gratefully acknowledges the valuable discussions with Dr.A. R. Thomson, A.E.R.E., Harwell.     

Sigmoid shape of the oxygen equilibrium curve and the P50 of human hemoglobin

The fractional saturation of hemoglobin with oxygen was plotted against P/P₅₀ and the slope of the abscissa at 1 was calculated for 38 OEC data sets of human Hb A. There was a linear correlation between the slope and the Hill coefficient (n_max), and the slope was about one-forth that of n_max. This implies that the slope of the abscissa at 1 of Y vs P/P₅₀ plot can provide information about the magnitude of cooperativity in hemoglobin oxygen binding.     

Preparation and oxygen binding properties of soluble covalent hemoglobin-dextran conjugates

Summary Stroma-free hemoglobin solutions present some drawbacks when used as blood substitutes, essentially because the hemoprotein has a low vascular retention, due to its small hydrodynamic volume. Covalent coupling of the protein with dextran derivatives artificially increases its size and affords polymeric conjugates whose oxygen-binding properties (Barcroft's curve, Hill coefficient) depend on the molecular weight.The authors wish to thank Prof. J. Neel and Prof. C. Vigneron for useful discussions and criticism.     

The chloride effect in human hemoglobin: A new kind of allosteric mechanism

In human hemoglobin hydrogen ions, chloride, 2,3-diphosphoglycerate and CO₂ cooperate to shift the oxygen equilibrium curve to the right. Bovine hemoglobin, by contrast, has an intrinsically low oxygen affinity: when stripped, it is as low as that of human hemoglobin in the presence of 0.1 M NACl+0.1 M DPG.     

On the relationship of hemoglobin oxidation with the conformation of hemoglobin

Summary The rate of hemoglobin oxidation by various oxidants was studied under aerobic and anaerobic conditions, and the mechanism of hemoglobin oxidation was discussed in relation to the conformation of hemoglobin.     

Functional properties of lyophilized hemoglobin in the presence of amino acids after 13 months of conservation

Summary Four lyophilisates of hemoglobin, each protected by an amino acid salt, were conserved for 13 months. The determinations carried out (oxyhemoglobin, methemoglobin, p50, Hill's number, and visible spectrum) demonstrated that the hemoglobin had retained its functional properties.