A study of fibrous long spacing collagen ultrastructure and assembly by atomic force microscopy

Abstract

Fibrous long spacing collagen (FLS) fibrils are collagen fibrils in which the periodicity is clearly greater than the 67-nm periodicity of native collagen. FLS fibrils were formed in vitro by the addition of ␣ 1 -acid glycoprotein to an acidified solution of monomeric collagen and were imaged with atomic force microscopy. The fibrils formed were typically ϳ150 nm in diameter and had a distinct banding pattern with a 250-nm periodicity. At higher resolution, the mature FLS fibrils showed ultrastructure, both on the bands and in the interband region, which appears as protofibrils aligned along the main fibril axis. The alignment of protofibrils produced grooves along the main fibril, which were 2 nm deep and 20 nm in width. Examination of the tips of FLS fibrils suggests that they grow via the merging of protofibrils to the tip, followed by the entanglement and, ultimately, the tight packing of protofibrils. A comparison is made with native collagen in terms of structure and mechanism of assembly.

Effects of Cysteine Proteases on the Structural and Mechanical Properties of Collagen Fibers

“…Only recently, the fine structure of collagen fibrils has been better understood (41). The morphology of collagen fibers is characterized by a regular arrangement of fibrils tightly bundled together through GAGmediated proteoglycan interactions as shown in previous reports (15,39,42,43). We and others (24) have previously demonstrated the unique collagenase activity of catK, which is able to cleave at multiple sites within the triple helical region of tropocollagen.…”

Nerve collagens from diabetic and nondiabetic Sprague–Dawley and biobreeding rats: an atomic force microscopy study

“…Generally, we observed clustered fibrils as also seen in [9,15,22]. Thus, we took an approach similar to that of Garcia et al [30], in which several particles were imaged in a single scan for data analysis; we did not attempt to image single fibrils as in [10,23,24,34]. Modeling details are provided in the Appendix.…”

“…A unique advantage of AFM for biological research is its ability to resolve topological features at the atomic scale without significant disruption of tissue. Indeed, the technique has been used extensively to measure structural changes in collagen fibrils, as summarized in the previous section [15,[22][23][24]. Unlike EM images, however, AFM images must generally be corrected for artifacts arising from finite tip sizes, cantilever angle and tip placement on the cantilever.…”

Stabilization of collagen using plant polyphenol: Role of catechin

“…It is the main structural protein of skin, bone and tendon [8,9]. Collagen as a protein has a distinguishing feature, each molecule has a coiled coil structure with three polypeptide chains, two ␣ 1 (1) and one ␣ 2 (1) chain, wound together to form a right handed triple helix of about 3000Å length and 15Å diameter [11]. Earlier the ultrastructure of collagen has been well elucidated [10][11][12].…”

“…Collagen as a protein has a distinguishing feature, each molecule has a coiled coil structure with three polypeptide chains, two ␣ 1 (1) and one ␣ 2 (1) chain, wound together to form a right handed triple helix of about 3000Å length and 15Å diameter [11]. Earlier the ultrastructure of collagen has been well elucidated [10][11][12]. Collagen is an important biomaterial finding several applications as prosthesis, artificial tissue, drug carrier, cosmetics and in wound healing.…”