Modular design of synthetic protein mimics. Characterization of the helical conformation of a 13-residue peptide in crystals

Journal Article · Tue Aug 08 04:00:00 EDT 1989 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00442a024· OSTI ID:5161348

Karle, I L; Flippen-Anderson, J L; Uma, K; Balaram, P ^[1]

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1. Naval Research Laboratory, Washington, DC (USA)

The incorporation of {alpha}-aminoisobutyryl (Aib) residues into peptide sequences facilitates helical folding. Aib-containing sequences have been chosen for the design of rigid helical segments in a modular approach to the construction of a synthetic protein mimic. The helical conformation of the synthetic peptide Boc-Aib-(Val-Ala-Leu-Aib){sub 3}-OMe in crystals is established by X-ray diffraction. The 13-residue apolar peptide adopts a helical form in the crystal with seven {alpha}-type hydrogen bonds in the middle and 3{sub 10}-type hydrogen bonds at either end. The helices stack in columns, zigzag rather than linear, by means of direct NH{hor ellipsis}OC head to tail hydrogen bonds. Leucyl side chains are extended on one side of the helix and valyl side chains on the other side. Water molecules form hydrogen bonds with several backbone carbonyl oxygens that also participate in {alpha}-helix hydrogen bonds. There is no apparent distortion of the helix caused by hydration.

• OSTI ID: 5161348
• Journal Information: Biochemistry; (USA), Journal Name: Biochemistry; (USA) Vol. 28:16; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
AMINOBUTYRIC ACID
AUTONOMIC NERVOUS SYSTEM AGENTS
CARBOXYLIC ACIDS
CHEMICAL BONDS
COHERENT SCATTERING
CONFORMATIONAL CHANGES
DIFFRACTION
DRUGS
MOLECULAR STRUCTURE
NEUROREGULATORS
ORGANIC ACIDS
ORGANIC COMPOUNDS
PEPTIDES
PROTEINS
SCATTERING
STEREOCHEMISTRY
X-RAY DIFFRACTION