Erratum: Crystal structures of collagen model peptides with Pro‐Hyp‐Gly repeating sequence at 1.26 Å resolution: Implications for proline ring puckering, Kenji Okuyama, Chizuru Hongo, Rie Fukushima, Guanghan Wu, Hirotaka Narita, Keiichi Noguchi, Yuji Tanaka, Norikazu Nishino, Biopolymers (Peptide Science)(2004)76(5) 367–377

Abstract

The original article to which this Erratum refers was published in

Correlation between Raman and X-ray crystallography data of (Pro-Pro-Gly)10

“…Therefore, these bands reveal secondary structure features and hydration level. The peculiar absence of intra/inter chain H-bond in the (PPG) 10 structure implies a relevant effect of the hydration patter to define the super-assembly [1,6]. The position of three amide I bands in (PPG) 10 crystals (1629, 1645 and 1669 cm -1 ) is in good agreement with previous FT-IR absorption spectra of (PPG) 10 solution [29].…”

“…If the 1200-1320 cm -1 region has a significant contribution of the non-canonical amide III bands expected for Pro residues, besides the CH 2 rocking-wagging bands, the comparison between experimental bands in the amide III region and predicted amide III frequencies is good for the Asher's equation [21] (see Table 2), but not for others [22]. Despite the hydration, accurately described in the structural studies [1,6], is not included explicitly into the successful semi-empirical equation [21], the agreement between experimental and theoretical frequencies in the amide III region of (PPG) 10 is quite good. Within this assignment, the strong putative amide III bands correspond to the two proline residues in X and Y position, whereas the very minor amide III bands correpond to the Gly amide bonds.…”

“…Successively, proline ring puckering of (ProHyp-Gly) 10 was re-examined using X-ray diffraction data collected at high resolution (1.26 Å) in order to obtain reliable information both at 100 K and room temperature [6]. At 100 K, all the seven Hyp residues in the asymmetric unit at the Y position show up puckerings, while proline rings at the X position take three up and four down puckerings.…”

“…Though the two equally intense bands at 564 and 543 cm -1 in Figure 1B might remind a doublet (568 and 546 cm -1 ) for ring bending II (mode 7 in ref [26]) of the two up and down isomers reported by Kapitan et al for Pro zwitterion, [26] the inspection of (PPG) 10 crystal Raman spectra does not indicate other predicted doublets. This observation can be explained with a higher abundance of down Pro conformation in (PPG) 10 crystals [1,4,6] or with a failure in extending DFT calculations on Pro zwitterion and Polyproline [26] to (PPG) 10 . In the last case, further computational analyses are required to definitively assign the bands corresponding to the two up and down isomers of proline rings in (PPG) 10 .…”

First-principles structures for the close-packed and the 7/2 motif of collagen

“…R-factors indicate that both structures describe features of the diffraction data [8,[13][14][15][16]. Therefore, the atoms have been assigned differently to the three strands and hence the assignment of the atoms to the individual strands remains uncertain.…”