title: Fragility of reconstituted type V collagen fibrils with the chain composition of α1(V)α2(V)α3(V) respective of the D-periodic banding pattern.
abstract: The triple-helical domains of two subtypes of type V collagen were prepared from human placenta, one with the chain composition of [α1(V)](2)α2(V) (Vp112) and the other with the chain composition of α1(V)α2(V)α3(V) (Vp123) with limited pepsin treatment. In order to characterize the triple-helical domain of the type Vp123 collagen molecule, the reconstituted aggregate structure formed from the pepsin-treated collagen was compared by using transmission electron microscopy. The diameter of the fibrils reconstituted from types pepsin-treated type Vp123 collagen and type Vp112 collagen was highly uniform and less than the D-periodicity at all the temperatures examined, suggesting that the major triple-helical domain of both subtypes has a potency to limit their lateral growth. Both fibrils were approximately 45 nm in width and showed the D-periodic banding pattern along their axes at 34°C. In contrast to type Vp112, the reconstituted type Vp123 fibrils showed no banding pattern along their axes when they were reconstituted at 37°C. The banded fibrils once reconstituted from type Vp123 at 34°C tend to lose their characteristic pattern within 60 min when they were incubated at 37°C. One explanation is that a slightly higher content of hydrophobic residues of type Vp123 collagen than those of type V112p collagen augmented the intermolecular interaction that disturbs the D-periodicity governed essentially by electrostatic interactions. Taken together with recent data in Col5a3 gene-targeted mice, the results suggest that type V123 collagen exists not only as a periodic banded fibril but also as nonfibrillar meshwork structures.
authors.affiliation: Shriners Hospitals for Children, Portland, OR, USA.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Mizuno
authors.forename: Hans Peter
authors.initials: HP
authors.lastname: Bächinger
authors.forename: Yasutada
authors.initials: Y
authors.lastname: Imamura
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Hayashi
authors.forename: Eijiro
authors.initials: E
authors.lastname: Adachi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D024062:Collagen Type V / Q000737:chemistry* / Q000648:ultrastructure; D005260:Female; D006801:Humans; D051379:Mice; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D010920:Placenta / Q000737:chemistry; D011247:Pregnancy; D011487:Protein Conformation; D011498:Protein Precursors / Q000737:chemistry*; D017433:Protein Structure, Secondary; D051381:Rats; D020539:Sequence Analysis, Protein; D013045:Species Specificity; D013552:Swine; D014020:Tissue Extracts / Q000737:chemistry
chemical_list: D024062:Collagen Type V; D011498:Protein Precursors; D014020:Tissue Extracts