Extinction coefficients k(lambda) for water at 25 degrees C were determined through a broad spectral region by manually smoothing a point by point graph of k(lambda) vs wavelength lambda that was plotted for data obtained from a review of the scientific literature on the optical constants of water. Absorption bands representing k(lambda) were postulated where data were not available in the vacuum uv and soft x-ray regions. A subtractive Kramers-Kronig analysis of the combined postulated and smoothed portions of the k(lambda) spectrum provided the index of refraction n(lambda) for the spectral region 200 nm </= lambda </= 200 microm.

Optical Constants of Water in the 200-nm to 200-microm Wavelength Region.

Publisher Summary Informational macromolecules, or semantides, play a unique role in determining the properties of living matter in the perspectives that differ by the magnitude of time required for the processes involved—the short-timed biochemical reaction, the medium-timed ontogenetic event, and the long-timed evolutionary event. Although the slower processes should be broken down into linked faster processes, if one loses sight of the slower processes one also loses the links between the component faster processes. The relative importance of the contributions to evolution of changes in functional properties of polypeptides through their structural modification on the one hand, and of changes in the timing and the rate of synthesis of these polypeptides on the other hand, constitutes a problem that justifies the study of evolution at the level of informational macromolecules. The evaluation of the amount of differences between two organisms as derived from sequences in structural genes or in their polypeptide translation is likely to lead to quantities different from those obtained on the basis of observations made at any other, higher level of biological integration.

Evolutionary Divergence and Convergence in Proteins

Publisher Summary This chapter describes hemoglobin and myoglobin. Hemoglobin and myoglobin are, among all proteins, ones that have been, and are, most actively studied; an enormous number of papers have been published over the past hundred years on all aspects of their properties and behavior. The study of these proteins has gone beyond the interest in their physiological role as oxygen carriers because they represent ideal models for investigating the properties of proteins in general, especially of enzymes. Correspondingly, current knowledge of the structure and function of hemoglobin and myoglobin is far greater than that available for any other protein. In spite of this, however, many questions still remain unsolved regarding the exact molecular mechanisms involved in the function of these proteins. Before discussing the properties of respiratory heme proteins, it is necessary to briefly describe some properties and reactions of their prosthetic group, mainly because the characteristic physiological functions of these proteins arise from the intrinsic reactivity of the heme.

Hemoglobin and myoglobin.

STUDIES of the regulation of human erythropoiesis and haemoglobin synthesis at different phases of development are hampered by the lack of a self-sustaining culture in which erythroid differentiation can be examined, and by difficulties in obtaining erythropoietic tissue in embryonic and early fetal life1. New insights into the regulation of murine erythropoiesis have been obtained by the study of established cultures of erythro-leukaemic cells (Friend cells) which can be induced to differentiate in vitro2. Recently, Andersson et al. 3,4 have reported that the K562 human cell line, obtained from a patient with an acute transformation of chronic myeloid leukaemia (CML) has properties in common with erythroid cells. In particular, cells of this line contain glycophorin and spectrin in their membranes and synthesise minute amounts of haemoglobin, detectable by radioimmunoassay. We have investigated the capacity of these cells to differentiate in vitro and report here that they are induced by haemin to synthesise large amounts of haemoglobin; preliminary analysis indicates that this is predominantly of the embryonic type.

K562 human leukaemic cells synthesise embryonic haemoglobin in response to haemin.

The chromosomal arrangement of human alpha-like globin genes: sequence homology and alpha-globin gene deletions.

THE methods described in the first paper of t h s series (Part I ; Bcavcn, Ellis and Whitc, 1960) for the estimation of foetal haemoglobin (Hb-F) have bcen uscd to dctcrminc Hb-F lcvcls at all stages of normal development from thc intra-uterine period to adult lifc, and also to establish the levels which may be cncountcred in children and adults suffcring from a variety of disorders of haemopoiesis and functionally abnormal states of the blood. Thalassacmia and the hereditary haemoglobinopathics will be discussed in Part 111.

Studies on human foetal haemoglobin. II. Foetal haemoglobin levels in healthy children and adults and in certain haematological disorders.

Human Embryonic Hæmoglobins

Human embryonic hemoglobins.

Oxidation of Phenyl-Hydrazines in the Presence of Oxyhaemoglobin and the Origin of Heinz Bodies in Erythrocytes

G. H. Beaven

Papers

Studies on human foetal haemoglobin. II. Foetal haemoglobin levels in healthy children and adults and in certain haematological disorders.

Human Embryonic Hæmoglobins

Human embryonic hemoglobins.

Oxidation of Phenyl-Hydrazines in the Presence of Oxyhæmoglobin and the Origin of Heinz Bodies in Erythrocytes

On the recombination of canine and human haemoglobins.