Complete amino acid sequence of the medium-chain S-acyl fatty acid synthetase thio ester hydrolase from rat mammary gland

Journal Article · Tue Mar 10 04:00:00 EST 1987 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00379a024· OSTI ID:6470364

Randhawa, Z I; Smith, S

The complete amino acid sequence of the medium-chain S-acyl fatty acid synthetase thio ester hydrolase (thioesterase II) from rat mammary gland is presented. Most of the sequence was derived by analysis of (/sup 14/C)-labelled peptide fragments produced by cleavage at methionyl, glutamyl, lysyl, arginyl, and tryptophanyl residues. A small section of the sequence was deduced from a previously analyzed cDNA clone. The protein consists of 260 residues and has a blocked amino-terminal methionine and calculated M/sub r/ of 29,212. The carboxy-terminal sequence, verified by Edman degradation of the carboxy-terminal cyanogen bromide fragment and carboxypeptidase Y digestion of the intact thioesterase II, terminates with a serine residue and lacks three additional residues predicted by the cDNA sequence. The native enzyme contains three cysteine residues but no disulfide bridges. The active site serine residue is located at position 101. The rat mammary gland thioesterase II exhibits approximately 40% homology with a thioesterase from mallard uropygial gland, the sequence of which was recently determined by cDNA analysis. Thus the two enzymes may share similar structural features and a common evolutionary origin. The location of the active site in these thioesterases differs from that of other serine active site esterases; indeed, the enzymes do not exhibit any significant homology with other serine esterases, suggesting that they may constitute a separate new family of serine active site enzymes.

• Research Organization: Children's Hospital, Oakland, CA
• OSTI ID: 6470364
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 26:5; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACID SEQUENCE
AMINO ACIDS
ANIMALS
BIOLOGICAL EVOLUTION
BODY
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CHROMATOGRAPHY
CYSTEINE
DNA
ENZYMES
ESTERASES
GLANDS
HYDROLASES
LABELLED COMPOUNDS
LIQUID COLUMN CHROMATOGRAPHY
MAMMALS
MAMMARY GLANDS
MOLECULAR STRUCTURE
NUCLEIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANS
RATS
RECOMBINANT DNA
RODENTS
SEPARATION PROCESSES
THIOLS
VERTEBRATES