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Verification of simple hydration/dehydration methods to characterize multiple water compartments on Tendon Type 1 Collagen
Author(s) -
Cameron Ivan L.,
Short Nicholas J.,
Fullerton Gary D.
Publication year - 2007
Publication title -
cell biology international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.932
H-Index - 77
eISSN - 1095-8355
pISSN - 1065-6995
DOI - 10.1016/j.cellbi.2006.11.020
Subject(s) - chemistry , dehydration , tendon , hydration energy , monolayer , titration , molecular mass , biophysics , analytical chemistry (journal) , crystallography , molecule , chromatography , biochemistry , anatomy , organic chemistry , medicine , biology , enzyme
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 h m = 1.6 g/g which divides into primary hydration on polar surfaces h pp = 0.8 g/g and secondary hydration h s = 0.8 g/g bridging over hydrophobic surfaces. Primary hydration is hydrogen bonded tocollagen polar side chains h psc = 0.54 g/g with small free energy or to the protein main chain hydration h pmc = 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 ofthree non‐bulk water compartments on collagen ( h pmc = 0.26 g/g, h pp = 0.8 g/g and h m = 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 h Ra = 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.