No abstract

A cDNA clone encoding a pectinacetylesterase (PAE) was isolated from 3-day-old mung bean seedlings using PCRbased techniques. Degenerate oligonucleotide primers were designed according to the N-terminus and internal peptides from the purified PAE. The full-length clone of 1453 bp codes for a signal peptide of 24 amino acids and a mature protein of 375 amino acids. The Mr and the pI of the cDNA-deduced amino acid sequence agree with the values estimated for the purified enzyme. No significant sequence identity between the PAE and any known protein could be found in the databases. Northern analysis revealed developmentally regulated expression of the mRNA in mung been seedlings.

Cathepsin L was purified from chicken liver lysosomes by a two-step procedure. Cathepsin L exhibited a single band of Mr 27,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions, presented a high affinity for the substrate Z-Phe-Arg-NMec, was very unstable at neutral pH, and was inhibited by Z-Phe-Phe-CHN2. The complete amino acid sequence of cathepsin L has been determined and consists of 215 residues. The sequence was deduced from analysis of peptides generated by enzymatic digestions and by chemical cleavage at methionyl bonds. Comparison of the amino acid sequence of cathepsin L with those of rat liver cathepsins B and H and papain demonstrates a striking homology among their primary structures.

No abstract

No abstract