Small-angle scattering studies show distinct conformations of calmodulin in its complexes with two peptides based on the regulatory domain of the catalytic subunit of phosphorylase kinase

Journal Article · Tue Oct 09 00:00:00 EDT 1990 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00492a003· OSTI ID:6072601

Trewhella, J; Blumenthal, D K; Rokop, S E; Seeger, P A ^[1]

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1. Los Alamos National Laboratory, NM (USA)

Small-angle X-ray and neutron scattering have been used to study the solution structures of calmodulin complexed with synthetic peptides corresponding to residues 342-366 and 301-326, designated PhK5 and PhK13, respectively, in the regulatory domain of the catalytic subunit of skeletal muscle phosphorylase kinase. The scattering data show that binding of PhK5 to calmodulin induces a dramatic contraction of calmodulin, similar to that previously observed when calmodulin is complexed with the calmodulin-binding domain peptide from rabbit skeletal muscle myosin light chain kinase. In contrast, calmodulin remains extended upon binding PhK13. In the presence of both peptides, calmodulin also remains extended. Apparently, the presence of PhK13 inhibits calmodulin from undergoing the PhK5-induced contraction. These data indicate that there is a fundamentally different type of calmodulin-target enzyme interaction in the case of the catalytic subunit of phosphorylase kinase compared with that for myosin light chain kinase.

• OSTI ID: 6072601
• Journal Information: Biochemistry; (USA), Journal Name: Biochemistry; (USA) Vol. 29:40; 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
BIOCHEMICAL REACTION KINETICS
CALMODULIN
ELECTROMAGNETIC RADIATION
ENZYMES
GLOBULINS
IONIZING RADIATIONS
KINETICS
MOLECULAR STRUCTURE
MUSCLES
MYOSIN
ORGANIC COMPOUNDS
PEPTIDES
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHOTRANSFERASES
PROTEINS
RADIATIONS
REACTION KINETICS
SCATTERING
TRANSFERASES
X RADIATION