Two-dimensional NMR and photo-CIDNP studies of the insulin monomer: Assignment of aromatic resonances with application to protein folding, structure, and dynamics

Journal Article · Tue Dec 12 00:00:00 EST 1989 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00451a046· OSTI ID:6969438

Weiss, M A; Shoelson, S E ^[1]; Nguyen, D T; O'Shea, E; Karplus, M ^[2]; Khait, I; Neuringer, L J ^[3]; Inouye, K ^[4]; Frank, B H; Beckage, M ^[5]

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1. Harvard Medical School, Boston, MA (USA) Massachusetts General Hospital, Boston (USA)
2. Harvard Univ., Cambridge, MA (USA)
3. Massachusetts Institute of Technology, Cambridge (USA)
4. Shionogi and Co., Ltd., Osaka (Japan)
5. Eli Lilly and Co., Indianapolis, IN (USA)

The aromatic {sup 1}H NMR resonances of the insulin monomer are assigned at 500 MHz by comparative studies of chemically modified and genetically altered variants, including a mutant insulin (PheB25 {yields} Leu) associated with diabetes mellitus. The two histidines, three phenylalanines, and four tyrosines are observed to be in distinct local environments; their assignment provides sensitive markers for studies of tertiary structure, protein dynamics, and protein folding. The environments of the tyrosine residues have also been investigated by photochemically induced dynamic nuclear polarization (photo-CIDNP) and analyzed in relation to packing constrains in the crystal structures of insulin. Dimerization involving specific B-chain interactions is observed with increasing protein concentration and is shown to depend on temperature, pH, and solvent composition. The differences between proinsulin and mini-proinsulin suggest a structural mechanism for the observation that the fully reduced B29-A1 analogue folds more efficiently than proinsulin to form the correct pattern of disulfide bonds. These results are discussed in relation to molecular mechanics calculations of insulin based on the available crystal structures.

• OSTI ID: 6969438
• Journal Information: Biochemistry; (USA), Journal Name: Biochemistry; (USA) Journal Issue: 25 Vol. 28:25; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
AMINO ACIDS
ANIMALS
AZOLES
CARBOXYLIC ACIDS
CONFORMATIONAL CHANGES
DIABETES MELLITUS
DICHROISM
DISEASES
ENDOCRINE DISEASES
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HISTIDINE
HORMONES
HYDROXY ACIDS
IMIDAZOLES
INSULIN
LEUCINE
MAGNETIC CIRCULAR DICHROISM
MAGNETIC RESONANCE
MAMMALS
MAN
METABOLIC DISEASES
MOLECULAR STRUCTURE
NUCLEAR MAGNETIC RESONANCE
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PEPTIDE HORMONES
PHENYLALANINE
POLARIZATION
PRIMATES
RESONANCE
SPECTRA
STEREOCHEMISTRY
TYROSINE
ULTRAVIOLET SPECTRA
VERTEBRATES