Conformational requirement of signal sequences functioning in yeast: Circular dichroism and sup 1 H nuclear magnetic resonance studies of synthetic peptides

Journal Article · Tue Sep 25 00:00:00 EDT 1990 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00490a017· OSTI ID:5870694

Yamamoto, Yoshio; Ohkubo, Tadayasu; Kohara, Atuko; Tanaka, Toshiki; Tanaka, Toshiaki; Kikuchi, Masakazu ^[1]

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1. Protein Engineering Research Institute, Suita, Osaka (Japan)

Recently, the authors have designed a series of simplified artificial signal sequences and have shown that a proline residue in the signal sequence plays an important role in the secretion of human lysozyme in yeast, presumably by altering the conformation of the signal sequence. To elucidate the conformational requirement of the signal sequence in more detail, functional and nonfunctional signal sequences connected to the N-terminal five residues of mature human lysozyme were chemically synthesized and their conformations in a lipophilic environment analyzed by circular dichroism (CD) and {sup 1}H nuclear magnetic resonance (NMR) spectroscopy. The helix content of the peptides, including functional (L8, CL10) and nonfunctional (L8PL, L8PG, L8PL2) signal sequences, was estimated from CD spectra to be 40-50% and 60-70%, respectively, indicating that the helical structure is more abundant in the nonfunctional signal sequences. Two-dimensional NMR analyses in 50% TFE/H{sub 2}O revealed that each peptide adopted a helical conformation throughout the sequence except for a few residues at the N- and C-termini. Furthermore, H-D exchange experiments indicated that the helical structure of the C-terminal region of the functional signal sequences (L8 and CL10) was less stable than that of the nonfunctional signal sequences (L8PL and L8PL2). On the basis of these results, a model was developed in which the functional signal sequence is inserted in the membrane with a helical conformation and the C-terminal helix unraveled in an extended conformational form through an interaction with the signal peptidase.

• OSTI ID: 5870694
• Journal Information: Biochemistry; (USA), Vol. 29:38; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
LYSOZYME
SECRETION
PEPTIDES
NUCLEAR MAGNETIC RESONANCE
HEAVY WATER
MAGNETIC CIRCULAR DICHROISM
MICELLAR SYSTEMS
PROLINE
PROTONS
YEASTS
AMINES
AMINO ACIDS
AZOLES
BARYONS
CARBOXYLIC ACIDS
DICHROISM
ELEMENTARY PARTICLES
ENZYMES
EUMYCOTA
FERMIONS
FUNGI
GLYCOSYL HYDROLASES
HADRONS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
HYDROLASES
MAGNETIC RESONANCE
MICROORGANISMS
NUCLEONS
O-GLYCOSYL HYDROLASES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXYGEN COMPOUNDS
PLANTS
PROTEINS
PYRROLES
PYRROLIDINES
RESONANCE
WATER
550601* - Medicine- Unsealed Radionuclides in Diagnostics