Alpha-amylase from the hyperthermophilic archaebacterium Pyrococcus furiosus. Cloning and sequencing of the gene and expression in Escherichia coli.

A gene encoding a highly thermostable alpha-amylase from the hyperthermophilic archaebacterium Pyrococcus furiosus was cloned and expressed in Escherichia coli. The nucleotide sequence of the gene predicts a 649-amino acid protein with a calculated molecular mass of 76.3 kDa, which corresponds well with the value obtained from purified enzyme using denaturing polyacrylamide gel electrophoresis.

The purification and characterization of an extremely thermostable alpha-amylase from the hyperthermophilic archaebacterium Pyrococcus furiosus.

The alpha-amylase from Pyrococcus furiosus, a hyperthermophilic archaebacterium, has been purified to homogeneity. The enzyme is a homodimer with a subunit molecular mass of 66 kDa. The isoelectric point is 4.

Amino acid residues essential for biological activity of a peptide derived from a major histocompatibility complex class I antigen.

The stimulatory activity of peptides from the alpha 1 domain of the major histocompatibility complex (MHC) class I antigen on adipose cell glucose transport was previously shown to require a preformed, ordered conformation of the peptide. The two peptides studied previously were Dk-(61-85) (ERETQIAKGNEQSFRVDLRTLLRYY) and Dk-(69-85). We now show that systematic alanine substitution in Dk-(69-85) identifies residues that are essential for biological activity.