Myoglobin

About: Myoglobin is a research topic. Over the lifetime, 4377 publications have been published within this topic receiving 151708 citations. The topic is also known as: uniprot:P02144 & MB.

Photolysis of the carbon monoxide complex of myoglobin: nanosecond time-resolved crystallography.

Abstract: The biological activity of macromolecules is accompanied by rapid structural changes. The photosensitivity of the carbon monoxide complex of myoglobin was used at the European Synchrotron Radiation Facility to obtain pulsed, Laue x-ray diffraction data with nanosecond time resolution during the process of heme and protein relaxation after carbon monoxide photodissociation and during rebinding. These time-resolved experiments reveal the structures of myoglobin photoproducts, provide a structural foundation to spectroscopic results and molecular dynamics calculations, and demonstrate that time-resolved macromolecular crystallography can elucidate the structural bases of biochemical mechanisms on the nanosecond time scale.

Role of iron in bacterial infection.

Abstract: Iron is essential for most living things. The importance of the metal lies in its remarkable capacity to engage in electron transport reactions in biological systems (Neilands, 1974). From the point of view of infection, a clear distinction must be made between the quantity of iron present in body fluids and its availability to bacteria. In the living body, iron is not freely available. The bulk of the metal is locked up in ferritin, hemosiderin, myoglobin, and in the hemoglobin in red cells (Lanzkowsky, 1976). The iron-binding proteins, transferrin and lactoferrin, which possess only a minute fraction of the total body iron, are normally only partly saturated with Fe and have an exceptionally high association constant of about 1036 for the metal. This means that the amount of free iron in equilibrium with these proteins is only about 10−8 M, which is far too low for normal bacterial growth. To obtain Fe from normal tissue, bacteria must therefore possess iron chelating agents with association constants similar to those of transferrin and lactoferrin. In injured or dead tissue the situtation may be very different. For example, the lysis of red cells can provide large amounts of Fe for those bacteria that can assimilate heme compounds.

Hemoglobin and myoglobin.

Abstract: 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.