Biomaterial Database

Characterization of exoskeletal proteins from the American lobster, Homarus americanus. 1998

M Nousiainen, and K Rafn, and L Skou, and P Roepstorff, and S O Andersen

Department of Molecular Biology, Odense University, Denmark.

Proteins from the calcified exoskeleton of the lobster, Homarus americanus, were extracted and separated by two-dimensional gel-electrophoresis. Electroblotting the proteins onto polyvinylidene difluoride (PVDF) membranes followed by sequence determination gave 16 N-terminal amino-acid sequences and revealed that further eight proteins were N-terminally blocked. The relative molecular mass, M(r), was obtained for most of the electrophoretically separated proteins by means of matrix-assisted laser desorption mass spectrometry (MALDIMS) after electroelution from Coomassie-stained two-dimensional polyacrylamide gels. Eleven proteins were purified from extracts of the exoskeleton by low pressure ion exchange chromatography and reversed-phase high performance chromatography, and their sequences were determined by combined use of Edman degradation and mass spectrometry. Good agreement was obtained between the M(r)-values measured by mass spectrometry and those calculated from the sequences. Five of the sequenced proteins contain two copies of a previously observed 18-residue sequence motif, while a couple of the remaining sequences show similarity to sequences of exoskeletal proteins from shrimps and spiders. Only limited similarity to insect cuticular proteins was observed.

UI	MeSH Term	Description	Entries
D008121	Nephropidae	Family of large marine CRUSTACEA, in the order DECAPODA. These are called clawed lobsters because they bear pincers on the first three pairs of legs. The American lobster and Cape lobster in the genus Homarus are commonly used for food.	Clawed Lobsters,Homaridae,Homarus,Lobsters, Clawed,Clawed Lobster,Lobster, Clawed
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D011506	Proteins	Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.	Gene Products, Protein,Gene Proteins,Protein,Protein Gene Products,Proteins, Gene
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013045	Species Specificity	The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.	Species Specificities,Specificities, Species,Specificity, Species
D017386	Sequence Homology, Amino Acid	The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.	Homologous Sequences, Amino Acid,Amino Acid Sequence Homology,Homologs, Amino Acid Sequence,Homologs, Protein Sequence,Homology, Protein Sequence,Protein Sequence Homologs,Protein Sequence Homology,Sequence Homology, Protein,Homolog, Protein Sequence,Homologies, Protein Sequence,Protein Sequence Homolog,Protein Sequence Homologies,Sequence Homolog, Protein,Sequence Homologies, Protein,Sequence Homologs, Protein
D019476	Insect Proteins	Proteins found in any species of insect.	Insect Protein,Protein, Insect,Proteins, Insect