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Biomedical subjects

M G Rossmann

Publications and source records attributed to M G Rossmann.

At least 181 records · Page 10Linked to original sources
PubMed1981

The structure determination of rabbit phosphoglucomutase.

Tetragonal crystals of rabbit phosphoglucomutase have been grown from solutions containing ammonium sulphate, polyethylene glycol solution and enzyme. There are two molecules, each of relative molecular mass 64 000 per asymmetric unit. A rotation function suggests that these are related by a twofold axis. X-ray diffraction data for five heavy-atom derivatives and native crystals have been collected by using oscillation photography. A tentative and partial solution of the KAu(CN)2 sites has been obtained. The enzyme in the native crystals is phosphorylated, but the phosphate can be removed without harm to the crystals. Similarly the essential Mg2+ ion can be removed or replaced by Zn2+. The enzyme is active in the native crystals.

Animals↗
PubMed1981

Structure and heme environment of beef liver catalase at 2.5 A resolution.

Most of the amino acid side chains of beef liver catalase were clearly identifiable in the 2.5 A resolution electron-density map, and the results are in good agreement with the sequence [Schroeder, W. A., Shelton, J. R., Shelton, J. B., Roberson, B. & Apell, G. (1969) Arch. Biochem. Biophys. 131, 653-655]. The tertiary structure of one subunit consists of a large antiparallel beta-pleated sheet domain with helical insertions, followed by a smaller domain containing four alpha-helices. The heme group is buried at least 20 A below the molecular surface and is accessible by a channel lined with hydrophobic residues. The proximal ligand is tyrosine-357, while histidine-74 and asparagine-147 re the important residues on the distal side of the heme. The inhibitor 3-amino-1,2,4-triazole, which has been shown to covalently bond to histidine-74, can be built into the heme cavity with its N(2) atom coordinated to the heme iron.

Animals↗
PubMed1981

An investigation of the active site of lactate dehydrogenase with NAD+ analogues.

The kinetic properties of 18 NAD+ analogues, with alterations to the nicotinamide moiety, have been studied with respect to dogfish, M4, rabbit M4 and beef H4 lactate dehydrogenase. The size of the groups present at C-3 of the pyridinium can be increased quite extensively without loss of coenzyme activity. Groups tested were thioamide, methyl, ethyl, diazoketone and chloroacetyl. Substitutions at positions C-4 and C-5 prevent proper positioning for hydride transfer and can hinder binding to the enzyme. The kinetic properties of pyridine-adenine dinucleotide and its 3-iodo derivative reveal the binding role of the amide at C-3 whereas 3-cyanopyridine-adenine dinucleotide is a strong inhibitor.

Animals↗
PubMed1981

Protein folding.

After some general remarks on protein structure, there follows a discussion on primary, secondary, and tertiary organization. The account of primary structure includes a discussion of the conformation of disulfide bonds. Types of helices, sheets, and turns are described in the section on secondary structure, followed by a discussion of super-secondary structure and the effects of metals and prosthetic groups of protein fold. The crux of the review lies in an examination of tertiary structure, or specifically of domains that are defined, in part, as functional units within a polypeptide chain. An assembly of domains can in turn result in a protein whose function is quite sophisticated. Some consideration of domain recognition is given in the section on taxonomy and in the appendix. The key part of the tertiary structure section concentrates on a taxonomic protein classification dependent not only on structure but also on function. A discussion of the requirements by quaternary structure on a fold are omitted in this review. Finally, no review of this kind can escape a discussion of evolutionary convergence and divergence.

Amino Acid Sequence↗
PubMed1980

The relationship between coding sequences and function in some heme binding proteins.

It is known that globin genes contain three exons with the middle exon coding for a four-helical supersecondary structure responsible for heme binding. Since this portion of the globin peptide chain can be structurally superimposed onto the cytochrome c and cytochrome b5 chains (Argos and Rossmann 1979), it can be inferred that the cytochrome c gene will contain only one coding sequence while the cytochrome b5 gene will be composed of three exons as found in the globin gene.

Amino Acid Sequence↗
PubMed1980

A structural comparison of concanavalin A and tomato bushy stunt virus protein.

Significant structural equivalence has been found among the polypeptide folds of the two tomato bushy stunt virus (TBSV) subunit domains and concanavalin A. This suggests gene duplication in the TBSV coat protein and leads to speculation on common functional properties of concanavalin A and viral coat proteins.

Chemical Phenomena↗
PubMed1980

Prediction of secondary structural elements in glycerol-3-phosphate dehydrogenase by comparison with other dehydrogenases.

The secondary structure of glycerol-3-phosphate dehydrogenase was predicted from its amino acid sequence. The pattern of helices and sheets within the first half of the polypeptide as well as specific marker residues were consistent with the properties of the NAD binding domain in other dehydrogenases. The second half of the sequence shows similarities with the catalytic domain of glyceraldehyde-3-phosphate dehydrogenase. The resulting two-domain structure of glycerol-3-phosphate dehydrogenase allows the correct environment for the B specificity of the nicotinamide ring and the L-glycerol 3-phosphate substrate.

Alcohol Oxidoreductases↗
PubMed1979

Structural comparisons of heme binding proteins.

Of the 82 three dimensionally characterized residues of cytochrome c551, 49 are found to be structurally and topologically equivalent to the globin fold and 41 are equivalent to the cytochrome b5 fold, with a respective root mean square separation of 3.5 and 4.9 A between equivalenced Calpha atoms. The common fold represents a central heme binding core, corresponding to the middle exon of certain globin genes. After superposition of the protein folds, the heme irons are found to be separated by 5.4 and 1.6 A, while their heme normals are inclined by 6 degrees and 32 degrees, respectively. Furthermore, the heme "face", determined by the asymmetric attachment of the vinyl and propionyl side chains, is directed similarly in all three heme proteins. The heme itself is rotated by 72 degrees and 116 degrees about its normal, respectively. The minimum base change per codon for the three pairwise comparisons corresponds to the expected value of random sequence comparisons. While all three heme proteins may have diverged from a common ancestor, their similarity may have arisen from the requirements of heme binding or the utilization of a particularly stable fold. Known structures within commonly accepted divergent families were superimposed in order to discriminate better between convergence and divergence. Minimum base changes per codon, number of deletions and insertions, percentage of equivalenced residues, precision of heme superposition, and root mean square separation of equivalenced Calpha atoms were tested as measures of evolutionary relationships.

Cytochrome c Group↗
PubMed1979

The structure of mouse testicular lactate dehydrogenase isoenzyme C4 at 2.9 A resolution.

The structure of lactate dehydrogenase isoenzyme C4 from mouse testes was solved at 2.9 A resolution using the technique of molecular replacement. The electron density map revealed a ternary-like configuration of the flexible loop peptide although density corresponding to the coenzyme and substrate molecules was not present. Apparently the apo-lactate dehydrogenase molecule in solution is in a dynamic equilibrium between the O (loop open as found in dogfish apo-lactate dehydrogenase M4) and C (loop closed as found in a variety of ternary complexes) conformations. During crystallization of the apoenzyme one or the other conformers is selected. The apparent stability of the closed conformation for the apo-lactate dehydrogenase C4 molecule may in part explain the low catalytic turnover number of the C isoenzyme. A possible substitution of an arginine residue at position 30 may also be a contributing factor as well as allowing NADP to act as coenzyme.

Amino Acid Sequence↗
PubMed1979

The tentative amino acid sequencing of lactate dehydrogenase C4 by X-ray diffraction analysis.

A tentative amino acid sequence of mouse testicular lactate dehydrogenase C4 was deduced from an electron density map and comparison with five other known lactate dehydrogenase sequences. The amino acid composition determined by chemical analysis agrees reasonably well with the present results. Necessary changes in amino acids were largely conservative and confined to the external portions of the molecule. Residues in the Q and P subunit contact regions were particularly well conserved as were most internal residues. The minimum base change/codon was similar between the C and H isoenzymes and between the C and M isoenzymes.

Amino Acid Sequence↗
PubMed1979

Metal-free southern bean mosaic virus crystals.

Native southern bean mosaic virus contains a significant number of Mg2+ and Ca2+ ions. These can be removed by treatment with EDTA causing the virus to swell by 7% in radius at alkaline pH values. The swollen virions are susceptible to protease and nuclease digestion. They are likely to be an intermediate during assembly and disassembly. Crystals of the metal-free virus have been grown and were found to be approximately isomorphous with the orthorhombic type III southern bean mosaic virus crystals (Akimoto, T., Wagner, M.A., Johnson, J.E., and Rossmann, M.G. (1975) J. Ultrastruct. Res. 53, 306-318), although the cell dimensions are longer by 2%. Native rhombohedral type II crystals disintegrate on changing the pH or increasing the ionic strength of the mother liquor. Damage can be prevented by addition of ethylene glycol. At alkaline pH values, these crystals also show a 2% increase in their cell dimensions as well as a significant alteration in their diffraction patterns. In the type II and III crystals, the viruses pack with only their 5-fold axes in contact. Thus, the difference of the apparent swelling in solution and in the crystals may be one of differential swelling over the virus surface.

Calcium↗