Crystallization, preliminary X-ray diffraction studies and Raman microscopy of the major haemoglobin from the

Antonello Merlino1, Luigi Vitagliano, Anna Balsamo

  • 1Department of Chemistry, University of Naples Federico II, 80126 Naples, Italy.

The blood of the sub-Antarctic fish Eleginops maclovinus (Em) contains three haemoglobins. The major haemoglobin (Hb1Em) displays the Root effect, a drastic decrease in the oxygen affinity and a loss of cooperativity at acidic pH. The carbomonoxy form of HbEm1 has been crystallized in two different crystal forms, orthorhombic (Ortho) and hexagonal (Hexa), and high-resolution diffraction data have been collected for both forms (1.45 and 1.49 Å resolution, respectively). The high-frequency resonance Raman spectra collected from the two crystal forms using excitation at 514 nm were almost indistinguishable. Hb1Em is the first sub-Antarctic fish Hb to be crystallized and its structural characterization will shed light on the molecular mechanisms of cold adaptation and the role of the Root effect in fish haemoglobins.

Related Concept Videos

Gene Families01:57

Gene Families

Gene families consist of groups of genes proposed to have originated from a common ancestor. Typically these arise through events in which a gene or genes are mistakenly duplicated during cell division. Unlike their parent genes (which are subject to selection pressure to maintain function), these gene copies do not need to preserve their sequences and may evolve at a relatively faster rate.
Occasionally these regions can be adapted to take on new roles within the organism, becoming novel genes...
Protein and Protein Structure02:15

Protein and Protein Structure

Proteins are one of the most abundant organic molecules in living systems and have the most diverse range of functions of all macromolecules. Proteins may be structural, regulatory, contractile, or protective. They may serve in transport, storage, or membranes; or they may be toxins or enzymes. Their structures, like their functions, vary greatly. They are all, however, amino acid polymers arranged in a linear sequence.
A protein's shape is critical to its function. For example, an enzyme can...
Globular and Fibrous Proteins02:21

Globular and Fibrous Proteins

Many proteins can be classified into two distinct subtypes - globular or fibrous. These two types differ in their shapes and solubilities.
Globular proteins are also known as spheroproteins and typically are approximately round in shape. They contain a mix of amino acid types and contain differing sequences in their primary structures. Globular proteins have many different functions, such as enzymes, cellular messengers, and molecular transporters. These roles often require the proteins to be...
X-ray Diffraction of Biological Samples01:10

X-ray Diffraction of Biological Samples

X-ray diffraction or XRD is an analytical tool that utilizes X-rays to study ordered structures such as crystalline organic and inorganic samples, polycrystalline materials, proteins, carbohydrates, and drugs.
According to Bragg's law, when X-rays strike the sample positioned on a stage, the rays are  scattered by the electron clouds around the sample atoms. The  X-ray diffraction or scattering is caused by constructive interference of the X-ray waves that reflect off the internal crystal...