To correlate the Raman frequencies of the amide I and III bands to beta-turn structures, three peptides shown to contain beta-turn structure by x-ray diffraction and NMR were examined. The compounds examined were tertiary (formula: see text). The amide I band of these compounds is seen at 1,668, 1,665, and 1,677 cm-1, and the amide III band appears at 1,267, 1,265, and 1,286 cm-1, respectively. Thus, it is concluded that the amide I band for type III beta-turn structure appears in the range between 1,665 and 1,677 cm-1 and the amide III band between 1,265 and 1,286 cm-1.

Amelogenins, a class of sparsely phosphorylated hydrophobic proteins characterized by a high concentration of Pro, Gln, Leu, and His have been implicated in the mineralization of tooth Recently a unique primary structure of bovine tooth enamel amelogenin was reported by Takagi et al.,3 characterized by repeating tripeptides Gln-Pro-X near the C-terminal region. Recent CD, Fourier transform infrared, and Chou-Fasman predictions of the secondary structure4 of the lower molecu- Lagant et al.7.' and Krimm and Seaton (see Refs. 9 and 10, and other references cited therein). In addition, Raman spectra provide information on the side-chain conformations of certain aromatic amino acid residues. EXPERIMENTALPreparation of the major highest molecular weight bovine amelogenin from developing premolar teeth has been previously de~cribed.~ Raman spectra were obtained with a Spex Industries Ramalog 5 Raman spectrometer equipped with the computer Spex SCAMP. A sample of amelogenin in aqueous solution was placed in a capillary tube and was illuminated using the 514.5-nm excitation line of an argon-ion laser (Spectraphysics model SP-164). A green interference filter was used to eliminate plasma lines of the laser. The signal was averaged from 10 scans by SCAMP data acquisition processor. Deuterated amelogenin was made by dissolving amelogenin in D,O and then by lyophilization to recover the solid. The sample was again dissolved in D,O for

Summary. Peptidase substrate specificities of 9 venoms of poisonous snalces of Anstnihii ;md New Gniuea were investigated. Thirty-four jieptides (29 dipeptidcs and .' ) tripeptldes) were u.sed as substrates. The peptides Cly-T.

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