Abstract
A molecular model of collagen hydration is used to validate centrifugal dehydration force (CDF) and re-hydration isotherm (RHI) methods to measure and characterize hydration compartments on bovine tendon. The CDF method assesses fluid flow rate from flexor and extensor tendons expressed in (g-water/g-dry mass-minute) and hydration capacity of compartments in (g-water/g-dry mass). Measured water compartment capacities agree with the molecular model of collagen hydration [Fullerton GD, Rahal A. Collagen structure: the molecular source of tendon magic angle effect. J Mag Reson Imag 2007;25:345-361; Fullerton GD, Amurao MR. Evidence that collagen and tendon have monolayer water coverage in the native state. Cell Biol Int 2006;30(1):56-65]. Native tendon hydration has monolayer coverage on collagen hm = 1.6 g/g which divides into primary hydration on polar surfaces hpp = 0.8 g/g and secondary hydration hs = 0.8 g/g bridging over hydrophobic surfaces. Primary hydration is hydrogen bonded to collagen polar side chains hpsc = 0.54 g/g with small free energy or to the protein main chain hydration hpmc = 0.26 g/g with greater free energy of binding. The CDF method replaces the more time consuming water proton NMR spin-lattice dehydration (NMR titration) method, confirms the presence of three non-bulk water compartments on collagen (hpmc = 0.26 g/g, hpp = 0.8 g/g and hm = 1.6 g/g). This CDF method provides the most reproducible experimental measure of total tissue non-bulk water (TNBW). The re-hydration isotherm method, on the other hand, provides the most accurate measure of the Ramachandran water-bridge capacity hRa = 0.0656 g/g. The only equipment needed are: microfilterfuge tubes, a microcentrifuge capable of 14,000 × g or 4 MPa, a vacuum drying oven, an accurate balance and curve fitting ability. The newly validated methods should be useful for characterizing multiple water compartments in biological and non-biological materials by allowing direct measurement of water compartment changes induced by pH, co-solute salt, glycation and protein cross-linking.
Original language | English (US) |
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Pages (from-to) | 531-539 |
Number of pages | 9 |
Journal | Cell Biology International |
Volume | 31 |
Issue number | 6 |
DOIs | |
State | Published - Jun 2007 |
Externally published | Yes |
Keywords
- Centrifugation
- Collagen
- Fluid flow
- Glycation
- Hydration
- Hydration isotherm
- Tendon
- Water
ASJC Scopus subject areas
- Cell Biology