Interaction of calmodulin with the calmodulin binding domain of the plasma membrane Ca sup 2+ pump

Journal Article · Tue Jan 16 04:00:00 EST 1990 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00454a008· OSTI ID:6718575

Vorherr, T; James, P; Krebs, J; Carafoli, E ^[1]; McCormick, D J; Penniston, J T ^[2]; Enyedi, A ^[3]

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1. Swiss Federal Institute of Technology, Zurich (Switzerland)
2. Mayo Clinic, Rochester, MN (USA)
3. National Institute of Haematology and Blood Transfusion, Budapest (Hungary)

Peptides corresponding to the calmodulin binding domain of the plasma membrane Ca{sup 2+} pump were synthesized, and their interaction with calmodulin was studied with circular dichroism, infrared spectroscopy, nuclear magnetic resonance, and fluorescence techniques. They corresponded to the complete calmodulin binding domain (28 residues), to its first 15 or 20 amino acids, and to its C-terminal 14 amino acids. The first three peptides interacted with calmodulin. The K value was similar to that of the intact enzyme in the 28 and 20 amino acid peptides, but increased substantially in the shorter 15 amino acid peptide. The 14 amino acid peptide corresponding to the C-terminal portion of the domain failed to bind calmodulin. 2D NMR experiments on the 20 amino acid peptides have indicated that the interaction occurred with the C-terminal half of calmodulin. A tryptophan that is conserved in most calmodulin binding domains of proteins was replaced by other amino acids, giving rise to modified peptides which had lower affinity for calmodulin. An 18 amino acid peptide corresponding to an acidic sequence immediately N-terminal to the calmodulin binding domain which is likely to be a Ca{sup 2+} binding site in the pump was also synthesized. Circular dichroism experiments have shown that it interacted with calmodulin binding domain, supporting the suggestion that the latter, or a portion of it, may act as a natural inhibitor of the pump.

• OSTI ID: 6718575
• Journal Information: Biochemistry; (USA), Journal Name: Biochemistry; (USA) Vol. 29:2; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACID SEQUENCE
AMINO ACIDS
AROMATICS
AZAARENES
AZOLES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL FUNCTIONS
CALMODULIN
CARBOXYLIC ACIDS
CHEMICAL SHIFT
DICHROISM
FUNCTIONS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
INDOLES
KINETICS
MAGNETIC CIRCULAR DICHROISM
MAGNETIC RESONANCE
MEMBRANE PROTEINS
MOLECULAR STRUCTURE
NUCLEAR MAGNETIC RESONANCE
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OVERHAUSER EFFECT
PORINS
PROTEINS
PYRROLES
REACTION KINETICS
RESONANCE
TRYPTOPHAN